You've heard, probably experienced, this story already.
I tried to get two tickets from Anchorage to Seattle. $337 each, one way. The closest stop from Anchorage is one of the most expensive. So, out of frustration I checked Anchorage to LA. $197. With a stop in Seattle! So, the Seattle price isn't that expensive because of lack of seats. After all, we had to use two of those seats to Seattle on the way to LA. It's just because Alaska has most of the Anchorage-Seattle flights.
After working through the Alaska Airlines website we ended up with a trip to Seattle with a two day stop in LA. The whole thing comes out cheaper than if we had just flown to Seattle.
And the Seattle-LA-Seattle flights we took were full. So if they had had reasonable prices to Seattle and we hadn't gone to LA too, they could have sold our Seattle-LA-Seattle seats and ultimately made more money.
But we got to see my mom, got more miles, and spent more time going to and from and waiting in airports.