Here's the general concensus, which might be also labeled as news from the rumor mill.

1) All of the machines have the same chip for payout and play the same. (came from a good and reliable source involved in gaming in Las Vegas)

2) It seems that from some heavy players, it comes out to $17 average to win a strike.

Most casinos won't sell from the cage, because they want you to play the machine.

Some casinos won't sell from the cage, even though they have no strike machines. (go figure)

Years back people suspected a change in the machine reels. (although the reels have nothing to do with the payout computer chip!) It's possible that the percentages were changed back in the 90s?

Buying strikes online or for $10-$13 each might be a real "deal". Winning them by playing is much more fun.