My case was already 285 euro's.
Wow! Exactly what does a 285 Euro case DO that a case half that price won't?
I think I'd take the 1700, buy a six core AMD processor (only slightly less performance at a fraction of the price). Complete the system with fairly good mid-range components and still have enough money to buy a 1.5 Ghz G4 Mac Mini and a copy of MorphOS.