or labour costs (Ed Tim not having a go jus mentioning) but Storm had quite a few parts made outside of the team aka titanium waterjet cut, i beleive the gears were machined by someone else also parts for the arm???? not sure thou one of the boys can correct me on that, that always takes a fair amount of dosh up,

you could look at other this example:- motors from a skip, speedcontroller home made for 30quid, hardox 120quid, gears 80quid, battieres 100quid radio 80quid wheels 130quid including tyre bonding
and thats a half decent amount for a fighting robot
540quid 100kg robot storms what another 0 on that