It seems to me that there’s still a good market for older kit which isn’t keeping up with current standards. Bikes with 26″ wheels, 135mm rear hubs, QR dropouts, straight steerers, 9 speed drivetrains, etc, etc, are still as fun to ride as they ever were.
My current bike ticks all those boxes, and I’m loving riding it!
However, I have had to build that bike up with a keen eye on economy; which has driven going down the “older standards” route. I would imagine there are plenty of folks in a similar boat. So — yeah, the market is there, but the prices most likely won’t be terribly high.
Not sure if that helps you make up your mind what to do with your bike: I suspect the devil will be in the details of whether you’d get what you feel the bike is worth or not, which is hard to second-guess. Maybe worth researching e.g. previous eBay auctions to see what similar things go for as P-Jay said.