We were surprised, too, at the prices. But then we realized that the towns in Alaska only have 5 months each year to catch the cruiser's dollars, while Caribbean cruise ports have 12 months each year.
Each person would handle this differently. There are some relatively inexpensive tours in the various cities, but we wanted to get beyond the cities. We pretty much decided that our Alaska cruise would probably be a one time thing and we wanted to whale watch, take a floatplane, and do things unique to Alaska. Costly, yes, but I think it would have been worth it.
As you probably know, we would have left tomorrow if I hadn't broken my wrist last week. So the trip is on hold for awhile. But, when we reschedule, we plan to splurge in Alaska!