Can you buy a PC by $400€ and play the game?

I view stupid the retrocompatibility in a consola of Next-Gen (Xbox 360 and PS3). I have XBox and if i need play in a game of XBox, play with a XBox. Same in a PS2 game, i play in a PS2. BUT if all USA and Japan have a option by $600 or less and Europe have the same price but without it option, them i not pay for it.But if Sony down the price for quality/options/price balance. I view correct. But the down of price in Europe is a utopia.