Yeah cargodist's indeed broken. You could milk plenty amount of money by just setting up two airports far away.
Maybe try Simutrans. It's got actual economy simulation. I tried it and I didn't like it tho. I couldn't make a profit in that game and kept losing. :(
Simutrans requires a lot of care when initially setting up the network: get something small and profitable first, an industry chain that makes money. Then expand slowly, only when you have cash flow, connect everything for the passengers. If you find something is not profitable, sell the vehicles or send them do something else.
Wait... same like in real life you mean?