No way did MadWorld cost $9-12m for development, it's pretty low tech, the assets are incredibly simple (both models and textures), it had a fairly small team and the whole thing was made in about a year. If Sega was paying that much, then Platinum was robbing them. I would say $6-7m max, though the audio budget was probably proportionately high within it.
I would say Bayonetta was likely also pretty low budget for a HD game, probably around $15-18m. It's gorgeous, but that's due more to the art design and nothing in the game seems particularly expensive imo. The PS3 version not being developed in parallel or inhouse might've raised costs more than normal though.
Weirdly, out of all Platinum's games (released at least, Vanquish looks pretty high end), I'd say Infinite Space seems the highest budget for it's platform. Lots of cinemas, nice 3D and an insane amount of content. I'm not sure what average DS budgets are, but IS looks more expensive than most in about every facet.







