Many casual poker machine players don't know there are wide differences in the chances of winning, depending on the machine you play. Unlike reel-slots where you have no way of knowing what the proper payout odds are, all video poker machine payout-tables tell you exactly what you get for each card combination. Assuming the machine plays with a full deck and deals are truly random, you can tell whether you are getting a fair payout or whether the owner is keeping a larger percentage for himself. Full payout on Double-bonus is 100.17% with perfect play. A machine that pays only 9/7 pays out 99.11%. A sucker machine that pays only 9/6 pays out only 97.81%. Sounds like small differences, but if you play dollars at 500 hands an hour you are putting in $2500 an hour; you will lose almost $60 an hour to the 9/6 machine, even if you make NO errors, and there's no way to make it up with slot-club points. You are just playing for a lucky hit.

For double bonus poker and a machine that pays 10 coins for a full house and 7 coins for a flush, plus the usual payouts for other hands (1000 for royal flush), you will get all your money back if you play long enough. Note that the probabliities say you have to play 90 hours (!) on average to hit the royal, so you could be down a lot before getting it all back on one hand (Gene's point). This is a very 'streaky' game.

John's answer was correct, but he listed the full-house/flush in reverse order.