I would say 10:1 just for the fact that someone held onto them and used all that bank space. Once a player gets a lot of them, they usually get bypassed or vendored.
I think I recall somebody buying 40 for a pd a few months back. 10scapes for 1pd seems too steep of a price, but ade does have a point in that collecting and banking these are annoying. I just stopped doing it when I got over a hundred dolls. 20 scapes for 1pd seems fair to me. However people would very rarely buy dolls. @Aizen what did you pay for these?