I would recomend you get a psu with more wattage. Some video cards take 400 watts of power on there own. so just to be safe go bigger. also isnt everything over priced here, 89 euros for home premium thats like 117 bucks. well whatever.
btw the video card cost 519 bucks here. look here Newegg.com - ASUS ENGTX580 DCII/2DIS/1536MD5 GeForce GTX 580 (Fermi) 1536MB 384-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card its only 439.