My dad just did an Antarctica cruise (Russian ice breaker though). He had a wonderful trip and prefers doing stuff like that over cruising as its less commercial. They were transporting crew onboard to Palmer Station and it was the first time in 7 years that they were actually able to break through the ice and get to the dock at Palmer Station. Talk about an opportunity to tour that place and the stories he heard!
As for shopping, we too skip the lectures, bs and those coupon books that make you spend more to get stuff. Hurry, theyre almost sold out! Most of the time the cashiers ask if we are on one of the ships anyways. As for deals, depends on what youre shopping for. Gems-Id be very wary. Quality is a big issue-they may look nice, but if not mined correctly will crumble in the future. What they pass off as top quality tanzinites is a joke. Prices are not always better either. I found a same cut, color, etc diamond here in town for $2000 less. And as for shopping on board being cheaper, not always so. I found a Caribbean Hook bracelet for a lot less in St Thomas than what was offered for the same one on board the last night.