I have been looking into the same thing myself lately. This is what I have concluded thus far; though, my reserach is far from complete.
Portrait/figure work does sell in galleries, but you have to look to find the ones that seem to lean toward it, Here is
one. Don't miss seeing the works of Han Wu Shen while you are there. His Asian beauties are stunning!
Another good way to get a feel for the border between portrait and gallery/print works would be to look at Steve Hanks paintings. He is considered to be one of the top selling print artists in the US and his originals are carried by a gallery in Colorado (I think I am remembering that correctly). You can look at his works at the ARC Living Masters website
here.