You plan on building a gaming pc, And doesn't go well for this...
Have a look at eBay and classified. Check also this French site(leboncoin.fr). Very good deals on CPU's and MoBo. I got a 3770k one year ago for €150.
I'd go with:
- 3570k, €150max (boxed CPU's have a 3 years manufacturer's warranty).
- Z77 motherboard (asrock pro3/4, extreme 3/4) €50/60
- amd 7970/280x (preferably voltage unlocked) €130 max. If you can find one still under warranty, by S/Not, that's even better
- 2*4gb of ddr3, 1600MHz/CL8 or better (usually lifetime warranty or 10 years minimum) €50 max
That's €380/400
To buy new:
- PSU, 600W quality one (Corsair CX600M, BeQuiet pure power 550w, EVGA SuperNova...)
€50
- SSD 250gb €100 (Samsung EVO)
- HDD 1TB €70
- Whatever case you like for €40/60
That's +/- €650/700