Significantly less than one still sealed in the factory wrap. I've seen them offered for $700-850 recently, but I didn't see whether they sold at all, at any price.
Can you tell the difference between out of the paper but unfired, and out of the paper, fired 10 or 100 or 500 rounds, then disassembled, thoroughly cleaned and greased, reassembled and offered for sale as "unfired"? I'm not sure I can.
If you want a museum piece, it's worth whatever you or someone else is willing to give for it, or what the seller declines to accept for it. If you want to use it for shooting, the depreciation is pretty expensive for the privilige of believing you are the first to fire it.
Good luck.