Depends on which ones you have or are wanting to get.
Usually Raya, 1st & 2nd Shana, 2nd Aja, 2nd Kimber, Stormer can bring a bit more sometimes nude. The ones with the tight curls still on a Shana & Stormer might bring in a little more but really prices can be all over.
Jem usually is the most common doll. The most commond of the Jem dolls is 1st ed. Jem/Jerrica and Rock N Curl Jem. It's weird. A common Jem/Jerrica can bring $2 or it can bring $10. If you have a newer collector they are probably willing to pay more because they don't know better so prices are all over the board.