The intent of the COTS contracts was to procure launches for much less than the usual price by providing up-front payments in exchange for a block buy of future launches. Seems to have worked great. Commercial companies sign contracts like that on occasion, when they don't like the prices from their current suppliers.

because I have said that assuming that Musk's main goal with SpaceX is not to send the supply (or astronauts in near future) to Space Station. His main mission with SpaceX is to help create a self-sustaining city on Mars. It seems to me he is using government's space contract money to pay the bills till he achieves his main mission. In that sense, I'd say that Govt is helping him and not the other way around.