Actually Dan, that's the problem ... beaver just aren't worth that much anymore, and any one who has skinned a few, like me, knows they take considerable time and effort. At $20 a large, last price I heard, it's just not cost effective to trap them.
These animals can be a big problem on the lower river where beaver activity can have a significant impact on salmonid productivity.
Sadly, these lower river beavers are now urban animals and in the sight of hundreds of people and .... dogs. In the water. Lethal trapping, really the only practical solution, comes with liability issues that few registered trappers are willing to address.
You are right about it taking a lot of effort to trap a beaver, skin it and preparing the hide. 45 years ago I used to get $30 plus for a large hide.