I think it should be whatever it costs to keep the games in good shape and on location while still being able to either pay off the game or throw a few dollars in the bank.

Under price yourself and the machines go away and there won't be any exposure for the hobby. Over price and you'll drive people away. I've had people say $1 / game, that's expensive. I politely explain to them that the machine they are going to play costs $5,000 to buy for an entry level Stern. The owner needs insurance and has to pay for parts when it breaks, plus labor if they have employees like the operator in my area does.

Add that to a 50/50 split with the house, and the machine needs 10,000 plays (without breaking) to pay for itself. After that discussion, you normally see a light bulb appear above their head.