Here....just start picking out cases/parts on various seller sites and mock up a build in your mind/on paper and ask here if it's optimal for your budget/needs/etc & if the parts you picked are good or not quality wise.

From what I see u are at the 450$ range check ur local dealers for this config:
Athlon II X3 455 (3.3GHz, 95W, 1.5MB total dedicated L2 cache, 4000MHz HyperTransport™ bus, socket AM3) $79.99

ASUS M4A88T-M AM3 AMD 880G HDMI Micro ATX AMD Motherboard $79.99

AMD Entertainment Edition 4GB 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model AE34G1609U2 - $21.99

RAIDMAX Altas ATX-295WBP Black Steel / Plastic ATX Mid Tower Computer Case 500W Power Supply - $59.99

Western Digital Caviar Blue WD5000AAKX 500GB 7200 RPM 16MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive - $89.99

ASUS EAH6670/DIS/1GD5 Radeon HD 6670 1GB 128-bit GDDR5 PCI Express 2.1 x16 HDCP Ready Video Card - $99.99

In Total: $431.94

The prices are from Newegg...
Say ur price range and I guess a lot of ppl here can help u with ideas

NO DVD drive? How will he burn stuff?

Dude a DVD drive is 20-25$

SAMSUNG 22X DVD Burner - $15.99

I wasn't saying it wasn't in his budget just saying you forgot to add one into the costs. Also does he have his own monitor and keyboard/mouse? If not that'll be extra, though the kb/mouse shouldn't be much.

From OP's first post I've understand he wants a PC without Monitor/KB/Mice ;) I'm guessing he have them already... I forgot the DVD cause I rarely use it with all the external HDD's I have :)

The point is that preconfigured PC's sux big time and most of the times u can make better pc for less money ;)

You are preaching to the choir, pal. ;)

As for DVD drive well suppose they want to watch dvds on their pc or still buy or own dvd/cd based games. Just a thought. It's like why have a floppy drive when stuff is online now? Well some still have floppies they might want to use someday for nostalgia's sake and the like....etc.

I'd just buy a pc case with some slightly better parts with the difference. Win win? :)

And what's the point? You just go and configure a pc urself :)

I meant a pc case and slightly better parts as in not prebuilt but buying better custom parts in general. ;)

And that's why I made that config for the op ;)

You left out the cost of an operating system. If he's going to run Windows and doesn't already have a spare license key sitting around then that will add a minimum of $100 (for an OEM version). For low-end systems the cost of the operating system will often make buying from a manufacturer cheaper than building one yourself, as many manufacturers are able to get Windows for much, much cheaper than it's available to the rest of us.

Buy an OEM copy of Windows from Newegg/etc for cheap(you can do it if you buy any piece of hardware from them when buying the Windows copy.).

An OEM copy WIndows 7 from Newegg is $99.