Originally Posted by
lecale
This is what you call the "black market". Unregulated, unreported sales.
As to how it hurts others...stores offer "loss leaders", products at below cost, because they hope it will draw in store traffic and people will do the rest of their shopping at that store.
When someone comes in and cherry-picks only the loss leaders and buys in bulk, clearing out shelves, they are hurting the store because they are only buying products that the store takes no profit, or even a loss, on. That customer is costing them money, and is eliminating the chance for other customers to have a deal and be satisfied.