Waggs, the simple answer is you will just have to ring around to find out. Things change such as the reciprocal rights between Caloundra and Mooloolaba. A few years ago a mate got caught out if fuel at Hervey Bay and while he was a memeber of 1770 they didn't accept reciprocal rights. I suspect HB and TCB may since then but I doubt they would extend to 1770.
Generally if you're not a member they charge you double the fuel cost, for my mate the 11 kms we were from the harbour cost him close to $500 for an 8m tinnie.
Scott, or should we call you Ann, the cost seems to be a lot cheaper down here, mine is around $80.