The way I see it Galway will be slight favourites in their QF, against either Cork or a qualifier. Laois will have to win their qualifier game for Galway to even have to do anything, and even then for you to have any chance to lose your money they'll have to beat the eventual Ulster champions as well as Galway lose.
I can't see it. Like all bets, there is risk, but this looks like a 1/5 shot to me, not 8/15.
(Incidentally, if anyone is willing to put the bet on for me.....