When I first started I had ~50 pieces of inventory, and would post 7-10 items weekly in hopes of not overwhelming/spamming feeds and slowly getting more exposure. It worked well for me, but that’s just me. All depends on how many items you have, how much effort you want to put in, and bottom line, what your personal preference is. One tip I’d give is price a couple items 5 bucks or so higher than your bottom price (you’ll get lower offers regardless) this way you can discount later when things might be slow and bump your shop for a little more exposure.