Selling towers - keep getting bad actors/scammers when doing local pickup only.

Selling tower speakers and other high-$ gear locally just takes more time, usually to find a buyer.  Any local ad I make always includes "Cash or Zelle in person" in the ad.

In y experience, the serious buyers are usually easy to spot when they ask a simple question like, "When can you show/ demo these."  On FB, you can also see their profile, what town they live in, if local, sometimes they list their employer, etc.  You can see that they are a real person and perhaps someone with means if they have pictures of their other audio gear in their FB page.

Zelle is a bank wire, essentially.  There is no recourse or charge-backs by the buyer.  It's the only 100% safe electronic payment I know of, (for the seller). 

Venmo, Paypal, and the like are backed by a credit card to which the buyer could contact and file a claim/ dispute resulting in the seller losing out.

The other option would be to contact TMRAudio.com and see what they would offer for your speakers.  I've heard nothing but good things about them.