> If they thought they were being taken advantage of or manipulated then poor people wouldn't buy anything from dollar stores

I've seen people (whether they be college students or just people living paycheck to paycheck) talking about how they only have e.g. $5 USD to spend on groceries for the next two weeks (because that's how much they have in their bank account, and that's when payday is).

If your choices are "something you can pay for at the dollar store at a less-than-optimal unit price" or "something you literally cannot buy because its purchase price exceeds the number in your bank account" then you really don't have a choice.

Poor people don't want dollar stores; they just want to survive.