As noted,, a gun show will net you the most. Yes,, posting here can get some sales,, and I'm sure several members would possibly appreciate your offerings.
Yes,, a table at a gun show will cost you $60-$80 for the (2) day show. You also get in on the day before to set up. That also allows you to be the first to see what others are offering for sale.
You also get (normally) (2) passes as a table holder to get in the show w/o cost. That way,,, you can get a trusted friend to help you handle the sales, allow you a break, (bathroom, food etc.) And yes,, usually, the second day of the show is slower,, but can still be very good.
Yes,, it's a couple of longer days,, but I always approached it as a "job" in that I know what time I'll start, and what time I'll quit.
If you wish,, I can give you several small detail pointers to make it easier to do a gun show.
The Greenville gun shows are usually well attended, and offer a petty good chance of you selling a lot of stuff if your prices are fair & a bit negotiable. Especially if you approach it with a serious plan to actually sell stuff. MANY of the table holders are "regulars" and carry guns from show to show trying to get top dollar, and to buy from others very low.
Example; You have a gun to sell. GB shows completed sales of that gun averaging at $500. You put out the gun for $550.00. A potential buyer comes by, is interested, and offers you $450.00. You counter with $500 and he buys it. Win-win.
BUT,, if he is firm in his offer of $450,, you ask yourself; "If I went to a gun shop, and put it on consignment, how much would I actually get AFTER it sells for $550.00?? The gun shops etc will usually get 10%-20% if on consignment.
OR,, if you try to sell to a shop,, you will normally get an offer of $250 for a $500 gun.
The gun show sales cut out the middle man.
Heck,, depending upon my schedule,, if you needed a hand to work the gun show,, I'd offer to help.