After being an "op" for about 18 months I can assure you that aside from the few successful barcades there is little money in the actual operation of games (much like LTG, Vid, and others told me 2 years ago when I had a similar crazy idea) and most of the money to be made on pinball will actually be for the advantage of the bar in drink and food sales from new people coming into their business and the pins keeping them there.
Simply put, unless you have a prime location and a 100% cut of the pins you had better be doing it for the love of pinball. Finacially it just does not make sense. Even our best earning game on route would take MANY years to pay itself off and that does not include any maintainence time, parts, etc... That is just the cost of the game. Keep in mind you will need to be spending mulitple trips and hours proactively maintaining and cleaning games each week. Your beauties will get beat up and tons of blasting about so that is a big commitment side form your time.
Some will ask >> "Why do it?" and the simple answer is that it is extremely fun for me. I like hanging out with other pinheads, I like sharing what a good playing game is supposed to be like, I enjoy the albeit sometimes frustration of broken games which turns into new knowledge and troubleshooting capabilities, and I like that we have helped to make a new community for really cool people in our town which many of I never knew existed prior to putting games on route.
Pinball is F U N and extending your current pinball hobby into operating can be equally as much fun as you are having now, or it could ruin it all and make it a second job. It all really depends on your POV and WHY are you going to do it. If you are hoping to make money then there are tons of better ways to spend yout time and actually profit form your energy. If you are hoping to share your love of pinball, learn a ton, and like the personal growth it will bring you combined with likely some new friends, then I say go for it.
Pinball operating can be a real PITA, but it can also be sure rewarding on a personal level. There is not much better than seeing a local pinhead revel in a new high score or learning a new game or thw off times when you see the ocassional family enjoying your games and high fiving or cheering on a young kid that is getitng their first glimpse of the wonder of pinball!