Idea: allow selling BTC for dollars too. And to maintain balance on the machine, adjust the exchange rate dynamically according to how much dollar bills are re

Idea: allow selling BTC for dollars too. And to maintain balance on the machine, adjust the exchange rate dynamically according to how much dollar bills are remaining or how much room is left. So people will keep it balanced to their own benefit and to the benefit of owners who would pay the difference in exchange rates and not do emptying/filling by themselves.