Not to jinx any future purchases, but I've never been scammed, or even burned on GB in my 30-40 purchases. Instead, I've bought some major bargains.
If I see anything that looks suspicious about an ad for an item that I'm interested in, I'll skip it if the red flag is too serious (rarely has this happened on guns that interest me), or I'll communicate with the seller and see what I think afterwards. I've bought from several no-rating and low-feedback sellers (typically not from sellers with negative feedback) and got some of my best bargains from no/low-feedback sellers. Note however, my purchases on GB were almost always used guns (because not much of the new stuff interests me). Perhaps the major scamming happens on the new stuff where price is king and it's easy to put up an ad that's just like all the other ads, except for a bogus low price?
A couple years ago, about the time GB started collecting taxes for my state and also increased their buyer fees,
and the typical shipping charge was bumped by most sellers,
and gun prices had spiked to the point that I couldn't find anything that I wanted at bargain prices, I pretty much quit buying. I realized that I really didn't have any reason to acquire more guns because I have everything that I really want, and definitely more than I need. As a result, I haven't been an active buyer since 2022, and perhaps the scamming has gotten way worse and I just don't know. But historically IME, if you used decent judgement, it was a safe enough place to buy.
And keep in mind, if nobody had ever bought from sellers with minimal feedback, GB wouldn't exist.
Every seller made their first sale with no feedback and no ratings.
ETA: Now I'll probably get scammed out of a thousand bucks next time I try to buy something. That's just how it often seems to work for me -- run my mouth about something that's been good, and it crashes.