I think the prices for Jem cels are reasonable for the quality of the cels. Every cel I've seen has a very detailed production background and the animation quality of Jem was top notch. Jem cels are cheeper than GI Joe and Transformers cels. 

Here's a few Jem cels from my collection (none are for sale). The webpage still needs some work.
http://members.aol.com/starlghtmx  

Sincerely,
Kett Robbins