With the popularity of MP3 players and the like, CD players and CDs are fading fast. Couple that with the .biz, I just don't see a bright future for this domain name. Perhaps, though, CDs will become like the old LPs and they will be collector's items at some point, then perhaps the site will have a market. But for now, best I can appraise it for is low to mid $XX (if that, considering it's not developed).
'CD players' is a very popular term regarding Google search, the 'exact' global monthly search volume is 301,000, which is excellent. The .biz extension, however, is very unpopular and unknown for most of the Internet users. So I think this domain might be worth low $xxx for the right buyer, but it won't be easy to sell.