Quoted from Gatecrasher:
In the 70s pinball went from 5 balls per game 10 cents per play (3 plays for 25 cents) - to 5 balls per game 25 cents per play (5 plays for a SBA dollar).
From there it went to 3 balls per game 50 cents per play and that was pretty-much the end for pinball.
There were a few more interim price changes in there. After 10 cents/play - 3 for 25, it first went to 2 Plays for a Quarter. Then, (around the introduction of Capt Fantastic or so) it went to 1 play 25c, 3 plays 2 Quarters. Then, around the SS era, we saw the straight quarter per play with the bonus for the SBA dollar coin (but not for 4 quarters in most cases).
And 3 Ball reared its head early on too. I first encountered 3 balls when Space Mission hit the streets. It was the only 3 ball game in an arcade filled with pinballs. Needless to say, we didn't play it there, but instead, where it was available for 5 Ball play.
For the most part, although recommended by the Manufacturers, it was resisted by the operators for a long time. Sometimes, it was hard to change an "old location" to the new way of thinking.
I remember setting up Firepower new out of the box and we had recieved a Memo from our HO that was from WMS recommending 3 balls 50 cents. That was a tough pill for our regulars to swallow as we were 100% 5 Ball then. It wasn't until Black Hole were theyseemingly happy to pay 2 coins.