That is an interesting question. I don't think I will sell any AG dolls ever, but my daughter rarely plays with her 23" My Twinn. DD is 11 now, and I got her the My Twinn when she was a sweet kindergartener. The doll is perfect, and I could probably get a good price for it, but the thought of selling it tugs on my heartstrings. It is almost like selling a piece of my DD's childhood. So, the doll is unlikely to ever get sold.
IMO, sellers enjoy the idea that their former dolls will go to a new home and bring some happiness. I think that idea helps sellers part with their dolls. It has more to do with the sellers feeling good about bringing joy to a child or a collector, rather than that the idea that the dolls' feelings will get hurt.