It has been stated before, nobody, myself included thinks missionchief is a money grab in any way. The devs have built this game for the players, not for monetary value.
With that said, has the possibility of a higher coin reward for rank up been explored? Possibly the higher you go, Lieutenant, Captain, Batt Chief, ie. having a higher coin reward for the rank up, more than just 10 coins.
Maybe my idea is wild, unrealistic and too much to ask, but just a thought. Others?