I don't personally think so, but a lot of sellers in my area seem to think so. No way I would pay more than $350 for a used 336W, JM or not (and I would probably wait till I could pick one up closer to $300). While the JM guns are more desirable, they are neither rare nor collectible (the 336W model that is). I've seen asking prices as high as $600 for a JM stamped 336W - it won't sell anywhere near that but I do wonder what the heck the seller was thinking.