jjsimp: As far as the put together system from ebay or whatever that German forum is. If you go that route, avoid that cheap power supply. You want a name brand power supply with a little more power than that. The motherboard is a cheap brand and so is the memory. I'm not that concerned with the memory.
Leroux: I'm quite set on buying the
pre-built PC mentioned in the OP, rather than build one myself. Although the motherboard and power supply used in that probably aren't that good either, but everything else seems really good for the price. Any opinion on these, are they totally horrible or still acceptable?
Motherboard: Gigabyte GA-B85M-HD3 (Chipset Intel® B85 Express)
Power supply: LC-Power LC-500H-12 500 Watt
(You can see more details about the other components, if you search the page I linked to for "Datenblatt" and click on that word. Sorry for the German!)
The power supply is from a "grey zone" supplier. Not really a "no name = crap" model, yet in the cheap range. It retails for 25€. I didn't find anything on that model, but a French magazine reviewed the 550W version and found it to be a rebranded / relabelled 400W Huntkey PSU ! I'd avoid it...
The motherboard is a recent model, as you would expect with a Haswell CPU. It was released in June. Entry level boards are usually based on H81 chipsets. B85 chipsets are just above that. Then the upper tier is based on H87/Z87 chipsets Gigabyte used to be ok, but nowadays MSI, Asus and even some Asrock tend to do better.