Since I pretty much left this thread in the dust, I would like to give it a closure.
A few weeks ago I found a local seller that offered me a bunch a PC parts for a (in my opinion) a very good price. I got...
CPU: Intel Core 2 Quad Q8300 @ 2.50GHz
MOTHERBOARD: ASUS P5G41T-M LX2/GB/LPT
RAM: 2x2GB Kingston DDR3 Dual-Channel @ 1066MHz (mobo supports up to 8GB)
POWER SUPPLY: Cooler Master 520W (can't see the model right now)
CASE: Cooler Master Elite 430 Black
DVD DRIVE: LG
All of the above cost me 89 Euros (97 USD). That is no typo. Of course the parts are used and aren't exactly current or last gen. However for this price its a very good deal. Plus. it's still much better than my old setup.
I build the PC myself and I had a blast doing it. To my surprise I had no issues what so ever and it worked perfectly on the very first power on.
All I have to do now is get a graphics card. I've read that the CPU combined with a good GPU can run games (almost) as well as a modern CPU.