GF tickets go on sale for club members 24-7-2012. My conundrum

I've never been to a GF before and am considering getting tickets. My team are the Dogs and are looking really strong this year. But my conundrum is the family takes an annual trip down the coast and stay on the water that weekend. What to do??? Should I get some and sell if the Dogs get knocked out? I'd hate to cancel the family trip for a game without the Dogs.

Non members can get tickets 2nd August

Mischa,
For your trip down the coast - is it somewhere that accommodation availability is guaranteed at late notice (a week or two if the Doggies get knocked out late in the Finals Series), or is it somewhere you have to book. If the latter, is there a cost involved for cancelling the booking at late notice?
These would be the main factors for me if I had your conundrum.
If it were me and it were financially viable, I would plan for both, knowing that you could easily get rid of the tickets should the Doggies get knocked. I guess it depends on the availability/cost of obtaining/cancelling accommodation at late notice, for your trip. It can be a looooooong time between drinks, as I well know and to be there for that would be an amazing experience.
Good luck with your decision making.