For the nonce, try looking up and then reading on the actual production costs of mass-produced items (including processed foodstuffs), and the mark-ups along the way for transport, shipping, middlemen, and the like.
The savings from going overseas are the lower wage scales, lack of environmental regulations, and the like; the physics and chemistry of the production processes are identical.
Cheers!
Why compare them to a grocery store? Maybe show that their profit margin took a big jump since their foreign sourcing increased?