I have Stax Srx-MK3 Pro Pricing

Dunno. I got the SR-X MK3's & SRD.7 in 1984 for $254.
Use an inflation multiplier and adjust for condition.
If you're trying to sell it's as much as a buyer will pay.

I don’t know if there’s a way to do it online, but a Dutch auction is an interesting option in that it works in reverse of a typical option.  You start offering to sell at a very high price and gradually lower it, and the first person who bids wins.  Anyway, just a thought.  Best of luck 

The SRX-MK3 Pro are a completely different item than the MK3.

Thanks for the response.

Thank you for the Dutch Auction concept.