You can build cheaper as nightmare says and buy in netherlands is cheaper look at http://tweakers.net/pricewatch/ and 700 watt for 1 videocard is to much and use psu calculator ( google for it and you now what psu you need)
And why coolermaster psu there are cheaper psu and even good as coolermaster
And look for amd is also cheaper and good for gaming
And for 100 euro you can get 16gb mem ddr3 kingston 7-7-7
If you want to spend about 500 ore 550 euro you can build better a new system than upgrade and a 560ti you can buy for 200 euro
Look good over the internet and make your choise than
First make the choice what you want amd ore intel, than look for cpu, then coose motherboard, than mem for it, than videocard and what psu
A dvd/ rw you can get for 20 euro
And a new case , a good one you can buy for about 65 euro with cable manegment I self have here the haf x and haf plus they have big fans 200mm.
There is a lot of choice take your time for it
