It's the other way around, 80 MS points = $1. Yeah, Nintendo's system is a lot better than that, at least in NA, Japan, and continental Europe. The UK doesn't get that simplicity of conversion. Still, exact dollar (or euro or pound or yen) amounts and the ability to simply buy the game without having to add arbitrary amounts of proprietary currency to your account is the best method currently available, and should be adapted by Nintendo and Microsoft. (To be fair, Microsoft's Games on Demand games show the price in real money, so maybe they're moving in that direction.)