Then use the remaining $10.8 million on marketing, boxes, and distribution ;)
You're forgetting the developer kits (imagine how much those cost), licensing software (3D Studio Max/Maya/Visual Studio/etc. plus depending on the game engine chosen it could be anywhere from $50,000 to $500,000 just to license it), offices, large amounts of hardware for testing, extra pay during crunch before showings of the game and what-not, relocating employees when neccessary, and wonderful cash-whoring bureaucracy.
Estimate the costs for those as well.