I think MC does take a loss on those chips. The idea is just to get you into the store, maybe even get you to drive 50-100miles. They know you will buy something else to go with it and probably even come back and purchase something else.
IIRC some MC employee posted that yes, MC does take a loss on these sales in order to get customers in the door.
However I dunno if I'd drive a hundred miles each way just to save $70 or so - my time is a bit more valuable than that, plus there's the gas to consider (unless it's downhill each way
). Not that I drive a Hummer or anything, but still...