I've played those penny slots. IIRC, the max payout was $25.
I have an old 25cent machine.
It cost plenty, but you can get machines that take silver dollars for much cheaper.
Much harder to find the dollars to put in them.
One of my buddies has a couple slots in his pool room. I lived in Vegas for awhile, never was drawn to the slots. Did some poker, blackjack, and some roulette. I finally got burnt out on the gambling scene altogether.