It would seem clear that MS paid for Bio. Regarding Crysis Crytek themselves stated a number of times they started exploring PS3 console first and 360 some time later, so why not get the game out as soon as possible on the console you learnt on first and follow (probably no more than 6 months I'd guess) on the console you learnt on afterwards?
As for why the immediate 'moneyhats' for MS its because they do it more often, and not just in games industry, therefore for most people the notion they paid comes more quickly than for other companies.
People create conceptions of companies based on actions just as they do with other people and apply them automatically to their reasoning... and so far this gen MS seems to being paying for exclusives (or even partial exclusives like DLC) for GTA IV way more than anyone else.
The second factor is that in most cases too much of such behaviour tends to garner negative responses from people (i.e. MS 'unfairly' using money to gain afdvantage rather than relying on merits of its console, games, etc). Link this to recent fine and the long history of MS using similar tacticts to overcome Netscape, etc. and its pretty obvious a fair few people are going to start reacting negatively to them using money for exclusives rather than positively.
Human nature my friends!
Personally I think paying for exclusives should be frowned on. In fact I think exclusives in general should be frowned on. It's probably because my background is playing on PC, but to me a console exclusive is like a game than only uses Nvidia graphics card... a ridiculous attempt to influence the consumer.
Let the console/games stand or fall for themselves and developers should be encouraged to get titles onto all platforms possible - obviously due to different consoles not everything could be multi-platform but you know what I mean (I hope you do).
Too often the consumer ends up with shoddier services when money rather than results influences markets.