100m is pretty small fry compared to Toyota, Ferrari and Mclaren (and maybe even Red Bull ) who spend three or four times that per season, even Renault spend quite a huge amount although not compared to the other three (last figure for Renault I can find is just under $400m for 2008 season)
Renault where the first team to follow Ferrari in fighting against the severity of the budget cut proposals too (although that miight just have been Briatore, but I doubt it)
Honda didnt really provide that much budget in the grand scheme of things
Running the cars is the cheap bit - developing them is the expensive bit.
Honda did most of that for them. 5 wind tunnels running at points apparently.