B&W 803D2 for $4,500?

I've got the option to buy a pair of B&W 803d2 speakers in mint condition for $4,500 (from the original owner).  I currently have a pair of 804s speakers and an HTM3s center.  Should I jump at this chance?  I haven't really kept on top of recent pricing but this seems incredibly low.  Would the match with my center be just terrible, though?