Couple of problems:
First, MR stuff is NOT cheap. If anything goes wrong with the casting process, you're going to be out some moo-lah.
Second, it's an officially licensed product. If you're going to cast it, you better make sure it's for you own personal use. If you get caught selling a cast of someone elses product, you could get it real trouble.
That being said, if you spent the money on one and don't plan on reselling anything that you cast, yeah I'm sure you could do that.
Just watchin your back-