Arcades in the 90s used the countdown clock,more lives type buy in. You bought time, or they would make the game so seriously hard you had to feed it quarters

Arcades in the 90s used the countdown clock,more lives type buy in. You bought time, or they would make the game so seriously hard you had to feed it quarters to keep the game going. Paying on an instant 'hey you could use more ammo for 50cents' at a exploitive time is something I am surprised we did not see as a mechanic in arcades. But they probably would have if they had thought of it. But the idea of feed more quarters in to keep playing was most certainly there.