I call them "vultures". They used to attack me before I got my stuff out of the truck. I know most of them now, so I do not bend on price with them. I had people go through my boxes still on the truck. I have even seen my parts for resale with my tags still on them. Most of thr time I think to myself at least I sold the item. Now they can take it home
Well I can see both sides of this: As a vendor it is a little bit of a nuisance having them interested in your boxes before they are off the truck. AT the swap meets I go to, they will help you off load them into your spot so they can look through them right then and there. I have seen them purchase right away to "flip" them during the swap meet to someone else. They are educated on prices and does it drive the price up for the next guy. Now while I am not a fan of this method, if you do not find a way to do it that you can live with, Then you are the one they selling the item(s) to. So I ask the vendor politely if I can help them unload there items, they understand this is commonplace now. I am not at the same swap meet re-selling. BUT I continually purchase and sell items( as I purchase better or don't need them), and usually make a profit.
Turning a profit may be looked down upon depending on the item and situation, but the guy flipping is taking a chance on the item as well, and there are some guys that flip, that take bad chances or aren't knowledgeable enough and spend money on item they they will get the big bucks.
I think we all a story of a item we purchased, and then later felt taken. I have a family member that for
years used to buy and sell all sorts of items, from garage sales, newspaper ads (not much automobile stuff) and the re-sell it the next week. I admired how well he was able to spot a deal, and then turn around and make money on it.
Just my take.