I'm no mod or anything, but with the post count so low I, as a mere reader, would not mind seeing HA items for sale here as long as it's hobbyists and not businesses.
You'd almost certainly want to employ some of the posting rules used in the r/XXXXsales subs. Things like prepend your title with For Sale, location and item description. It would also make some sense to declare in your ad some guidelines to ensure a smooth sale like PP invoice and/or some verifiable reference to your credibility (ie - Heatware/ebay ratings). There naturally needs to be some sort of assurances on both sides of the transaction.
I very much miss the r/homelabsales sub, but I am never going back.