I feel your pain! I tried to sell a Stubben, older, but a close contact in excellent show condition. I listed it for $800 OBO to start, not really expecting to get that much for it. I expected some low-ish offers. People will do what they can to get the best deal they can. I figured we'd haggle a bit and end up at a reasonable middle ground, but I had multiple people offer less than $300 for a saddle listed at $800. I couldn't even counter offer on that.
The other saddle I was selling, I listed at $300 OBO. It was an older Nice, in good condition, fully functional, but out of style. I had people trying to convince me that a saddle without knee rolls wasn't worth its weight in trash and that I should just ship it to them for the cost of shipping and no more.
I also had the same local girl contact me multiple times about my Stubben claiming it was stolen from her barn. It was bought out of state and I still had the receipt to prove it, as well as the original tags from when it was new.
It took me more than six months to sell them, but with patience I did manage to sell both saddles to the right buyers for reasonable prices.
Now I'm trying to sell a Show coat that's one size too big for me, and a show shirt that's one size too small. I have them listed on ebay and posted them in tack trader groups on facebook. I have had zero interest in them thus far. I have a feeling I'll just have to wait for someone needing those particular sizes to come along and it might take a while!
I sold a horse online too. That was even more of a nightmare than selling the saddles! I was brutally honest in my ad. The horse I was selling was NOT beginner safe. She was high maintenance and required near daily rides to stay sane. She also had a history of aggressive behaviors and I left no detail out. I still got a call from a middle-aged woman recovering from a back injury, and a mom looking for a first horse for her daughter. I outright said "no" when these people insisted on coming to try her out. Again, with patience, and after enduring many frustrating phone calls, I sold her to an event trainer with the right skills to bring her on.
Selling online takes an extreme amount of patience. I'm glad I don't do it for a living!