Um, with due respect, some of us on this forum are refugees who were banished fr. the TGP realm for whatever reason. That prevents us from viewing your sales.
To insure equal and a wider viewing audience, eBay has been my choice of auction or sales site because of Reverb's recent fees increase. If perhaps you've got some good feedback built up there, your items will more easily sell. You can choose either an auction or fixed price format (the listing window options have been updated and sometimes are hidden to discourage certain choices; be aware that unless you select "change" to fixed price sale, your item will sell in auction format). The usual constraints exist towards where you wish to ship and what countries you exclude, if perhaps you choose international shipping.
Be advised that your eBay account offers discounted shipping because of the carrier's connection to eBay. You'd need to research what Reverb's policy is towards shipping or wait for someone to chime in on this.
Reverb, likewise, offers a fixed price or Best Offer option. I've discovered that the Reverb site is glutted with PRS, so your chances of selling within a short time are decreased, unless you price accordingly for quicker sales. (Hoping you won't view me as a naysayer, and not saying you won't receive your asking price, just stating the Reverb market is glutted with PRS.)
Regards TGP, you don't have the same seller's/buyer's protections that either eBay or Reverb provides, so there is more risk involved selling on TGP. If something arrives damaged, TGP will not step in and handle sales disputes. This is one reason to direct folks on TGP to either eBay or Reverb to conduct your sale within either of these 2 sites, not directly on TGP.
Regards FB Marketplace, I'm not sure of their seller's/buyer's protection. That being said, on occasion, a couple of transactions have gone through for both buying and selling, and the caveat is local pickup only caters to a regional audience. My experience with FB Marketplace is that folks who do not have an eBay or Reverb account, or have been banished fr. either place are more likely to incur suspect deals or scammers; same with Craigslist.
FB Marketplace is trying hard to correct this and maintain its reputation, but it's almost a given that buyers and sellers need to be upfront, posting numerous images and describing the time for sale implicitly. On several occasions, I've needed to ask the seller specific questions that have resulted in a dealbreaker, and a non-sale for the seller.
Just so your item has plenty of images and a good description, I'd otherwise refrain using FB Marketplace...