I do it all of the time, though any salesperson thoroughly qualifies the potential buyer. I use Craigslist exclusively for local sales but Offer UP and Facebook Marketplace can work as well. Have sold dozens of items on Craigslist, as recently as last week, and have never had a scammer. Though there are plenty of flakes, but that just comes with the territory. YMMV. Summer is also, historically, the slowest time of the year for audio sales.
I would think that Austin would have a very vibrant used audio scene, like we have here in Portland OR. Sometimes it just takes time and patience. Good luck with it.