Did you think that when Microsoft's Games on Demand service launched, it'd be an egalitarian wonderland where every game would be the same price around the world? Well sorry. That's not the case.
The service (well, the listing for it; you can't download the games yet) is popping up all over the world for those signed up to Microsoft's new dashboard preview, and along with the game listings are game prices. Not every game seems to have turned up yet, but most have.
Some of them are fine. They're exactly what you'd pay at retail for the game, and although you could say that's still a rip-off (since your digital product lacks a box and printed manual), that's how digital delivery rolls these days. Sorry.