Don't forget an aircraft such as the C-17 isn't used just for terminal to terminal operations such as an airline with it's 747. The aircraft has to be capable of carrying all that stuff, and unloading / loading itself without GSE.
Then throw in military specific fitment such as EW. Anything Milspec and you can add a few zero's on the end. However, it's probably best to wait to see what the project actually includes (e.g. I know for a fact it includes mission planning systems etc too).