Why are there so many framing shops?

Bryan Caplan poses the question.  My answers:

1. This is a U.S. phenomenon, driven in part by framed photos of family members and regular turnover of decoration in one’s house.

2. The real value is often advice on which frame to buy.  This requires a reliable expert on hand and keeps framing shops small and artisanal in nature.

3. Frame shops lure people in to view and buy other overpriced items, such as pre-framed posters.  You need a separate shop for each variety of garish bad taste out there.

My puzzle is different: why is framing so expensive?  The frames are just finished wood, which you could import or buy cheap at a lumber yard.  The framing labor is often immigrants.  Yet a good framing job can cost more than a refrigerator or washer/dryer set.