Chronicle no longer has a sale forum. English Tack Trader and Horses Sales and Stuff are good on FB if you keep an eye on your post and keep bumping items up. Size and price may be your problem (or even description). I’ve been able to sell lightly used Ariat breeches, snap collar show shirts, and half pads well. I wasn’t able to sell a high end RJ show coat in size 4L or my saddle, people wanted these items much cheaper than what to me was reasonable for the qualiy. The saddle went to iselltack.com and my coat sold for a great price at equineexchangepa.com but both took a few months to sell, and at the consignment store I only get store credit so I lose less $$. Ultimately I was happy because I used the credit to buy a brand new One K in matte black so I pretty much traded something that I didn’t want for something I did.
As far as marketing your stuff online… what key words are you using to describe your items? Do they have stretchy technical fabric? Machine wash? If it is something that people may not know the original price, I usually include that so people know the original retail value v. what you are asking so they feel like they’re getting a good deal. Also, if it is anything other than TS Trophy Hunters, provide measurements and size comparisions so people know wha to to expect.