I would not advice eBay. That is where we sell our junk. Also I think you would be better off buying a whole new or rebuilt camera. A used camera goes for about $150 or so. Buying the board is taking a chance that it is really ok.
Wal-Mart is selling a complete p3s for $399. You might do better buying that one and selling yours on eBay. Sell as a working drone with a broken camera. Or upgrade to a p4.