My guess is that you are coming off a cruise in Seward and dropping off in Anchorage. The reason that this is so expensive is that is the exact same thing that many people want to do. The competition is really limited and nobody really picks up in Seward unless you are coming off a cruise, so they got you.

When I went to Alaska last year, I ran into the same situation. So, what I did was take the cruise line's bus up to Anchorage Airport and then I just picked the car up there. It was like $30/day for the car rental by doing it this way.