bud...the idea is to get product from vendors at the best possible price so they can pass the savings on to their customers....and turn a profit based on volume sales....
Evidently that's the idea some have, personally I'd prefer toys without lead, baby formula without mercury, beef without e-coli, or sneakers and clothing without exploiting kids to make it.
But to surmise professional corporate buyers have no idea why a particular vendor is markedly cheaper is naive.
Reebok International corporate headquarters is a stone throw from my home. Years ago all shoe production was moved from locally (Brockton, New Bedford) to Vietnam, China, Korea, Malaysia etc. why? Because shoes could be made by children in unventilated sweat shops, where working conditions including breathing paint and glue all day every day wasn't a issue.
Believe me, in a general sense, buyers know where and how products are being supplied to them.
But your spot on, the absolute goal is lowest price, that for should.