I'm selling some pretty expensive gear on eHam right now (FTdx-9000 package, Ameritron ALS-1300 - $6,600 in total) and was pretty concerned about getting ripped off by a dishonest buyer with PayPal. From what I understand, a buyer can simply claim that the goods were not as promised and get a refund from PP.
I listed acceptable payments as cash (in person pickup / meetup), US Postal Money orders (which the PO can verify as genuine) or Zelle (not reversible). I suppose I could also accept Western Union or Moneygram, but didn't think of it. Those are also not reversible.
I have seen forged bank checks that have a legit account number on them. If you deposit that check, it will take your bank 4-6 weeks to figure out that the check was forged. That's when they demand repayment in full by you.
These forgeries are VERY good, complete with watermarks and micro-printing. They are literally undetectable as forgeries, even with bright lighting and a strong magnifying glass.
Several years ago, my wife received one out of the blue. It was drawn on Wells Fargo Bank for $8,000. The idiot scammer didn't realize that we'd look at the postage stamp, which was from South Africa. That got shredded pretty quickly.
I don't know about the particular deal you're talking about, but it does sound like you're paying a middleman, which raises a red flag. That alone would make me walk away.
As for me, I'm really hoping to find a local buyer or to bring the gear to Dayton or NEAR-Fest this spring.