[s_forbes]

If you already have spares for most of the control system components, the material cost of a second robot is all you need to worry about. This can fluctuate a lot year to year depending on your design. If you have a lot of off the shelf transmissions, performance wheels, or specialty parts, the cost can go up pretty quickly (billet aluminum performance wheels seem great until you have to buy 12+ of them). I think the material costs of our practice robots have ranged from around $1500-$2500.

One nice thing about the second robot is that you don't have to sink any additional money/time into R&D, which can be a significant amount of the robot build budget.