I'm looking for my magic coin price list.. but it disappeared! First you have to determine which magician's coin you have and if it's sellable. For example.. I would not want to buy half of a Folding Quarter, that's the magic coin that you can fold in half or 3 parts so it could fit through the neck of a glass bottle. I believe you once found a Kennedy Half Shell with the other 2 sided Foreign and Kennedy reverse coin gimmick?
I suppose you could go into eBay and see what various types have sold for? Then look at what's offered for sale. Not too complicated.
Maybe they didn't realize it was a Magicians Type Coin. I once lost a 2 Headed Nickel (Both sides Obverse gimmick) and a gag Nickel that squirted water. Put them by accident into my regular change. Lost them both forever They vanished!