Don't worry, I try never to scratch records!!
I'm not sure what you'd call them, I don't think it'd be a boot sale. A flea market is where a bunch of people with some of their stuff to sell, mostly stuff they don't want anymore and are willing to let it go pretty cheaply, gather together in a single location and sell their wares to anybody that happens by and is interested. Nobody actually sells fleas. There's too many dogs that are MORE than willing to GIVE them away!!