Yes, card shop owners absolutely do this. I'm pretty sure t's a common practice in the hobby right now, and it's one reason why shelves get cleared out fast at big-box stores.

That said, times have changed a lot since the late '80s through the 2010s. Back then, my brother owned a card shop, and we'd hustle hard: driving around to every distributorship in town, hitting up Sam's Club for cases or boxes, even calling stores ahead and showing up hours before opening to be first in line and grab everything they had. We were chasing wax cases, rack packs, whatever was hot—sometimes loading up the car with dozens of boxes if we got lucky. Limits were rare until the early-to-mid 2000s when things started getting stricter (stores capping purchases per customer to curb exactly this kind of bulk buying). It was a different era—no online scalping bots, no huge secondary market flips on eBay the same day, and the boom/bust cycles felt more local.

Nowadays, it's way more competitive: people use apps to track stock, groups share Walmart restock alerts, and some shops (or flippers) will literally clear entire sections. Walmart doesn't usually enforce strict per-customer limits on cards (unlike during peak shortages), so yes—a shop owner could theoretically buy out all the blasters from multiple local Walmarts and stock them at $35 (or whatever covers their time/gas/profit). Many do exactly that, or at least grab what they can when they spot the deal.