I can't think of many products that one would buy that would retain its purchase value unless its there are limited supplies which doesn't seem to be the case any longer with this title. Buy it to play and enjoy. I'm getting one to keep. I won't be selling it anytime soon so resale price is the last thing on my mind :-/
I can't see someone buying a slightly used MMR for close to 8k when they can buy a new one for the same price.