I was at the airport and played new modern SS for .50 per play. Generally, pinball manufactures designed their games to last 40 seconds per ball (quoted directly from Gary Stern in an interview). Considering and assuming your games are in nice cosmetic and mechanical condition, I would pay 2 plays for a buck.
Today's player would rather play a SS game title. Us older guys have a mental barrier that a buck a game is too much money! Or, at least this older guy!