Only buy the ultimate beverage package if you are an alcoholic. You probably need to drink 10 drinks per day to break even with the cost.
Don't do the cruise shore excursions (way overpriced). Book independently and you'll probably save over 50%.
Don't buy premium dinners or chefs table. These aren't worth the extra cost. I've always found the normal dinners quite good.
Expect additional charges like an extra $15 a day for house keeping and 18% gratuity on drinks to be added to the bill and not part of the cost you have already paid booking the cruise. They always add these costs on your account at the end.
Expect the pool and chairs by the pool to be crowded each day. Got to get up early to claim a chair.
Do go and see the shows on the cruise theatre and comedy acts.
Do get off the boat at the ports and see the city.
Sounds great - would love to see Antarctica that way, although I suppose apart form those sightseeing flights there is no other way. I know what you mean about the price though, we (sisters and brother) just booked the folks on an anniversary cruise (50th) to the Kimberley through this mob and there was no change from $25k for the two of them.. Was something that they've been wanting to do for ages and it does look great, but so it should for those prices!
Been on 2 cruises, one to Vanuatu and stops along the way, didn't mind it. Then went on one that departed from Cairns and went to Milne Bay and absolutely loved it, lots of snorkeling and mingling with the locals, beautiful part of the world.
I am in my late 50s though but there were plenty of young people on the Milne Bay cruise.