$50 in a month is realistic in many locations.
50/50 split with locations that know the biz, new locations will sometimes accept 25/75 because they don't know any better.
Back in the day, a machine might cost $2000 and a replacement ramp $15.
If a ramp cracks nowadays (often $125), you might be out 3-5 months earnings (and the ramps are much more brittle now than when they were new).
A new machine is $6000 and would take 8000 plays (@ 75 cents) to break even. If your game gets 150 plays a month, it will only take 5 years to pay it off.
In 5 years, you have replaced many parts (bulbs, transistors, plastics, rubbers), have shopped the game, came out to unstick balls, swapped the game with others (2x a year or so you have to freshen up your line up as the till starts to go down), paid for your gas and time, paid insurance, paid city and state vending license, paid Uncle Sam, and paid 50% of your income to the bar owner.
Still think you can make a profit?