So, within the next four months or so I'm looking to be able to save up about six fifty I can spend to build a computer. In doing so, I'm looking to build a good, stable gaming rig that is fairly up to date without being high cost. Here is the setup so far:

--I'm perfectly fine with building it myself. I haven't done much major work since the days when 266 MHz was considered blazing fast, but I'd hope I can apply those skills still today.
--This is a unit that is going to be used as a media center/game system/network hub type thing.
--While I want to be able to get decent graphics, I'm not too concerned about being bleeding-edge or anything. I don't see the point of super-high resolutions, and since this thing will be used on a 720p HDTV it won't be going beyond 1366x768 anyhow, nor do I particularly care for anti-aliasing, aniscropic filtering, and so on. Jaggies don't bother me, but I'd like to be able to use a few fancy lighting effects and such.
--Hard drive space is not a major issue to start with.
--I already have a copy of Windows to put on it.

So far this is what I'm looking at (on Newegg):

--ASUS DVD Burner 24x
--LIAN L1 Lancool PC-K58W mid-tower case
--Western Digital 250 Gb HDD
--ZOTAC ZT-40702-10L GeForce GT 440 GDDR5 graphics card
--Dablotek DA Series PSDA500 500W power supply
--Kingston 2GB DDR3 RAM x2
--BIOSTAR H55A+ LGA 1156 Intel H55 motherboard
--Intel Core i5 Lynnfield 2.8GHz

This totals about 601 USD with shipping. Given my requirements, and that most people here are undoubtedly better with the hardware aspect of things than I will ever be, not to mention more experience shopping for such, do you see any way I could bring this down to closer to the 500 USD mark if possible? The less it costs the sooner I can get it, and the sooner I get it the sooner I can take advantage of being able to play some of the games I have that I don't play much due to my laptop's crappy 8200M G.

You should list the price of your components as well. Makes it easier to suggest lower cost alternatives. At a quick glance though, I'd guess you might save a few bucks by going with an AMD build. As well, Lian Li cases tend to be pricey. You might save a few bucks going with another brand (perhaps Coolermaster?)

You can buy a 1TB Hard drive for $60, so buy a 1TB HD.

Lian Li makes great cases, but usually pricey. But the one you picked is priced just right and looks awesome... plus has lots of nice features that a lot of similarly priced cases don't. That is a good choice. I'd buy that case today if I needed a case.

Research your PSU... there are too many unreliable brands made with cheap parts. You aren't saving money if you buy a cheap PSU only to have it fail and take a motherboard out with it. Plus, I honestly like to overbuy my PSU. Honestly, I have an Ultra x4 1200 Watt PSU (retail at the time was about $350) because I got a deal so stupid I had to take it (it was free, brand new, from a friend who reviews hardware) But if not for that, I'd have gone 800 watts not because I "need" it but because the overhead offers a measure of safety and better longevity.

I love my i5 Intel chip. The i5s do not support Hyperthreading so if video editing or fast Photoshop rendering is important, go i7... otherwise, your i5 will deliver great performance at a better price.

Oh... and in four months, your list will be entirely different :-)

I spent $1500 on my last build a year ago, but I also bought a 27 inch monitor, 8 GB of Ram, an ATI HD 5870, and a crapton of other stuff... Plus, the chip and RAM was a little more expensive then.

Another thing... I love NewEggs reviews. I mean, you never actually see one review that is all that helpful, especially since a lot of those guys think they know more than actually do... but if there are many reviews, you can spot trends in the comments that might signal a red flag or a good buy, so they are helpful.

I'd definitely double up the RAM.

He's running 4 Gigs (2GB x2)

I run 8 because I do use Adobe apps and I like having the extra RAM, but I don't think the extra RAM helps with most gaming.

Still, I do tend to agree that more RAM is a cheap and effective way to make any PC better, especially with Win 7 64-bit.

Sorry, I missed the "x2" at the end.

Hehe :P Really, the limitation on time is probably less than four months, but more than two. One aspect of this build I was looking at IS the time frame, since I'm hoping that by the time I get around to building it the parts will have dropped in price a little more.

While I understand where you're coming from with the 1 Tb HDD, I'm not sure about it for several reasons. One, the forty dollar price difference is pretty significant. Two, at any one time I doubt I'll have enough games/programs/etc. installed to even use up the entire 250 Gb drive I selected. Three, all of my music/game installs/etc. I keep on a passport drive, and will continue to do so so that, when I do build the set-top-ish unit, I can move it back and forth between the two and have all my files up to date at all times. Besides, if I end up needing the space, well, the unit has five 3.5 drive bays -- I can wait until I need it, then order one and drop it in, easy peasy.

Depending on how much things run, though, I might do the RAM upgrade, maybe to a single 4 Gb stick to start with. We'll see.

My main concerns were the motherboard and graphics card. Any comments there?

Gonna have to go with this xD

4 months can be massive in pc land :) For a ballpark figure somewhere it's ok I guess, but for specifics, better to ask when you have the money and are ready to buy :)

Have you considered a Saphire HD 5770, it has very similar results to your card in tests but it should be $20 or $30 cheaper.

I'll look into that, thanks!

In truth the build above isn't probably the best I could do even on my own, since I was kind of rushed (I set it up in about an hour, before heading off to work last night.) That being said, most of what it includes is basically what I want, and virtually identical to my previous endeavors to plan out this computer in case I decide to build it piecemeal.

In fact, the biggest change this time around from previous versions is an i5 in place of an i3 and an upgrade to DDR3 RAM.

ATM you're build looks pretty solid and you could stick to it and buy at reduced prices but if you're happy to spend to your limit, like a few others have said, give yourself a few days when you've got the capitol and have look again then.

Worth keeping an eye on things like Toms hardware but don’t take it as gospel when it’s down to the gubbins. As much as metrics are a good base, the perceivable differences on the actual running of your system between the majority of the mid to high range components will be pretty much negligible. Even though the prices rarely reflect this...

Well, I'd have thought that the radeon 5770 remained somehow more expensive than a GT 440.

Coming back to the main question

Why do you go for the ageing lynfield ? I personnaly would opt for a sandy bridge platform.

I'd start with this : http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.631830
add 4 GBs of memory , a decent good quality 600w PSU, a li-on or LG DVD burner, a functionnal case and a 500GB HDD ( 250 GB is a bit short nowadays, and a WD caviar blue 500 GB is only 6 USD more expensive than the 250 GB )

Now, the GPU. Fermi GT440 and radeon 5670 are reasonably priced, retain some accelerator capability but will perform 50% under a 5770 ( 20-30 USD more than the 440 unless I'm mistaken ) . Gigabyte's Radeon 5670 and Geforce 440 (http://www.newegg.com/Product/Product.aspx?Item=N82E16814125366) actually look quite attractively priced

Or you could have a look at this BIY kit : http://www.newegg.com/Product/ComboBundleDetails.aspx?ItemList=Combo.634257, where you just need to add the GPU of your choice

I cant be arsed to go on newegg and do price checks and get lost on there site for 5 hours but some quick notes...

Dont get a geforce GT 440, Try and get a ATI 5770 or even a nvidia GTS 450, Just a little extra to pay but the extra performance is worth it.

DONT Cheap out on a PSU Diablotek get quite crappy reviews on a lot of units, and quite unreliable, Everyone wants to save money when buying a PC but i do really recommend you to buy a high quality power supply, If im correct the PSU you are looking at is $25 Oh dear.

At the price range theres nothing good (IMO) Until you get in the $50 - $75 range, Seasonic is great but personally i dont like there cheaper range of PSU's Antech is also a decent brand some products are meh but some are great quality same goes with corsair but they do have great support i have heard.

At the bottom line make sure you AT LEAST have a 80 Plus unit, if you got a cheapo PSU and it blew up the chances are most your stuff may of gone with it, Thats why i advise EVERYONE to not cheap out on PSU's Thats also why some pre-built pcs look like a great deal but have some crap PSU inside.

-- [i]Myself i do talk about PC's from a gaming perspective so sometimes i may ask people to get better stuff that they may not even use, Currently i have a XFX 850W Black edition PSU 80 Plus silver, But i would totaly spend £120 over here on a seasonic X 650W 80 plus gold,
I tend to care about reliability just as much as how fast my PC should be.[/i]

Case is fine, Good quality but there are cheaper ones that are built just as good.

The i5 you have chose is great and i own the same one, Even though im a intel fanboy i would suggest taking a look at AMD phenom II CPU's they tend to be capable of pretty much the same as intel's products at a smaller price point, But in benchmarks and and stuff intel always comes out on top, And just better overall :3

I hope i have helped a bit. :)

Thanks everyone for all the help so far! You've given me a lot to think about.

Keep it coming, so I can see what to do when the time comes!