Interesting question, but I think the issue is confused a little. I don't know squat but aren't there two issues: the Copyrighted material, your intellectual property, and the Trade Mark rights of the floppy manufacturer?
You are selling a limited use right of your copyrighted material, on a trademarked medium that carries an intended resale right.
Regardless of any added value, you can resell floppies unless expressly forbidden; really the only restriction is the cost you pay as opposed to the resale cost, which is a business decision rather then legal. If I were to go to the the XYZ floppy factory and buy a case of floppies at wholesale and then go to a street corner, I could resell the XYZ floppies at the cost that either I agreed to with XYZ or the market price if there isn't a MSRP agreed to. But If I try to sell the floppies as TDK floppies well then I have a problem with TDK and their TM rights.
I think the only issue you would have is removing/replacing the manufacturers TM. But like I said, I don't know.
Yogi
EDIT: after a little searching I found this at DiskMakersDuplicator, printer, and blank media/supplies order terms
Intellectual Property Rights Protection
Disc Makers' Anti-Piracy Compliance Program protects property rights owners from the unauthorized distribution of their content.
Customers purchasing CD and DVD duplicators, blank recordable media, and other hardware and supplies warrant that they will use the equipment and media only for legitimate uses that do not infringe on the intellectual property rights of third parties.This seems to imply that for legally owned material, you are free to use their media and equipment for your own commercial purposes. I'm sure other companies have similar policies.
I knew I was right to pose the question to you guys. Thanks for posting that particular excerpt. It really helped clear things up a lot!
Now I can make my corny, nostalgia-fueled vision a reality!