I really doubt you're going to be able to download a new San Andreas wih MS only paying 50mil, Rockstar would lose a lot of money.
why would they lose a lot of money. their game and pricing is based on making an engine and making a game, the engine, tools to make levels and scripted story is all there and working, everything is done and making more content by that point is streamlined, quick and cheap. so thats the game, with whatever profits.
THen MS pay them 50mil to do more work build a quick city and so on, i mean how many designers does it take to build a city and how much time and on what wages, 50mil will easily cover that. You pay money to people to work, they work, thats how life goes. MS is paying them to do extra work on content for them, can't really see how hard that is to understand.
THe higher ups at Rockstar might well be making a few mil in wages, the level designers, texturing guys, these are normal guys on normal wages, 50mil will get a lot of work done. Rockstar aren't losing anything, they are simply going to spend extra time, to the tune of 50mil in man hours(probably significantly less to be fair) on content they would otherwise not have done and simply moved onto the next game.
ANyone that thinks the PS3 downloadable stuff will be comparable is just retarded. 50mil IS a lot to companies like Rockstar, this game will bring in a lot of money, but it cost a lot to make and gets heavily reinvested into next projects.