I agree. Most of them probably do steal. In my experience they certainly take as much money as they can from the most vulnerable customers they can find walk into the store.
Ever since I started frequenting Collectors Cache (now either the largest or one of the largest stores online,) I first noticed at their original store some 20 years ago (the very first time I walked in,) that they were not only pretty rude to the non-everyday customers, patronizing kids on the regular, price gouging literally every product, and offered almost nothing for trade-ins while overcharging for the cards/products they sold... but they also took advantage of kids (the younger the kid, the more they'd take advantage) by offering them even less than one would normally get for a trade in and charging more for whatever they were selling. Everyone else in the store would be ready to pounce with the bad trade offer if one of those kids ever happened to open anything good.
Even worse, I eventually found out that they were actually weighing the first edition base set booster packs.
They had two boxes, one that had been weighed for sure and one that I am assuming had not been weighed. Sometimes, if someone nice (like a new employee,) was working they'd let me choose which box I wanted my expensive ~$35 1st edition booster pack to be taken from but otherwise they'd just pull it from the box that had already been weighed. Plus, I didn't know which one had been weighed so I chose the wrong box the one or two times they allowed me to choose which was not the norm whatsoever. Much later, I remember seeing them go in the back one time before making a sale and I could actually see they had a scale.
I know it was weighed because both I and my friends never got so much as a holo from probably a half of a 1st ed. booster box of packs purchased individually at various times. At first, the 1st edition packs were something around $10. Then they were $25. Then $35. Then $55... etc and there's nothing wrong with the price increase as the price was just going up as they became more scarce. But to charge that much for packs that had been clearly weighed. I mean it was just blatantly obvious that they were weighing the packs and at the time I mentioned to my parents "It seems like they have a way to see what's inside the packs before they sell them, because every single time I buy a booster pack here it's literally garbage (ie. Lass, Clefairy Doll) and whenever we goto a different store or even Walmart I tend to get something good... and I had bought a lot more packs from CC." They told me it was probably in my head, but I literally had spent so much money and never gotten so much as a holo. They'd always try to get me to open the pack in the store if it was a 1st edition base set pack, too, because if something slipped through the cracks and I managed to pull something then they wanted to convince me to either trade it in for next to nothing or succumb to a bad trade offer from some older kid. "Oh, you're not going to open it in here?" "Nah." *Acts pissed*" And it was not even limited to the first edition packs either because the regular Base Set packs were also very clearly weighed almost right after the very beginning of release. The best thing I ever pulled from Collectors Cache base set packs was a (edit: Clefairy) and I had opened a ton. Always pulled Lass, Computer Search, Clefairy Doll or Devolution Spray. One time I got lucky and pulled Imposter Professor Oak. At the time I didn't know about weighing and I was just a little kid of maybe 10 to 11 years old.
Fast forward 25 years later and they've moved locations twice and are now one of the largest stores in the country, selling online. I don't know if they still weigh packs or if that's even still possible or not and they have toned down the taking advantage of people a little bit because they no longer need to do that and it's probably more beneficial for them not to do it in order to bring more people into the hobby as a whole. I will say they still are very stingy and act like you don't know anything about life if you don't know the name of the newest set release or the best pull from it. The store location is now large in size and right near me in location (a more wealthy area as compared to where they started, or the second location they had...)
Whenever I buy stuff now as an adult, I make it a point to NEVER give them my money.
P.S. I don't think this applies to all local game stores, because I never had the same bad experience at my other local game shops.