I guess I'm a bit odd, as I'm usually ok with most people. All the trades/purchases here have been really good.
Back when there were shops everywhere and any flea market had 3-4 dealers there were a few guys I had little respect for. Generally ones that didn't know much if anything about cards. Some were decent at business, and I respected them for that but not for card knowledge. I'd shop what I called the "clueless and obnoxious circuit" about every 3-6 months just to see what they'd lucked into. No big scores, but a few interesting cards cheap. A couple worn 49 leaf for .25 each because " those aren't in beckett so they can't be worth anything"
My favorite was the guy at the flea market who somehow got the impression I was some sort of bigtime dealer. Not really hard to understand as my usual response to his pushy sales pitch for new stuff was to tell him I already had it. So one day I tell him I'm thinking of selling some stuff at the flea market. He asks me to come around behind the van and I'm figuring he's making an offer for my inventory or maybe offering his- or maybe a threat- He was that sort of odd. Any way, he hands me 3 boxes of cards and says they're mine for free if I don't set up at the flea market! Probably about $45 worth of boxes at the time. Nice, a bribe from a dealer! I still feel bad about never letting on that I wasn't a dealer, just a guy with some extras to sell. But at the time the occasional free box of cards was a nice perk since I was making about $30 a week. He probably gave me 5-6 more batches of stuff over the next couple years.
SteveB