Counterfeit Muppets on the market

PuppetVision blog is concerned about people selling counterfeit muppets. He point out some for sale on eBay right now and questions what the motivation is for this?

In the age of ebay, there’s a booming and very profitable trade in film
and T.V. prop replicas on the internet and there’s a small minority of
replica builders who will build you a Muppet character for several
hundred dollars.

This is similar to the Star Wars replica lawsuits. It’s interesting to see that Lucasfilm draws a distinction between fan made replicas for use by the fan, and by replicas to be sold to others. (Link)