"Worth it" questions are the hardest. To me, no, because there's no salmon fishery within 200 miles of Anchorage, December is hardly salmon fishing season, it will be cold and dark, if you're flying coach it's an awful long way, and food prices are generally higher in Alaska than in the lower 48.
You could, for instance, fly to Seattle and get equally fresh fish, cheaper, and have plenty of things to see and do in the process. But fewer miles if it's a mileage run. Is that "worth it?"
For example, Dungeness crab is $4.99 a pound at most supermarkets here. How much is it in DC? Wild Alaska Coho fillets are the same price at my local Safeway as they are in the Carr's supermarkets in Anchorage. Shop at
Uwajimaya in Seattle (an awesome Asian supermarket/department store) and get some of the freshest and best seafood on the Pacific coast, eat lunch at their great little food court, and still have time to explore downtown Seattle, ride on a ferry, watch them fling fish around at the Pike Market, etc.
Don't get me wrong, I love Anchorage (former resident, still go for frequent visits) but flying there in December to save money on fish is only a great idea if it's mainly the
flying that's important.