Specification is not needed, even you assumed these were retail costs from the get-go,

they only compared retail costs

on the next sentence you conflated retail costs with consumer cost

they didn’t account for people

which of course they didn’t, retail costs will be the same even if the person getting the items isn’t paying for them.

When someone says “this is 30% cheaper now”, any reasonable person would understand that they’re referring to the retail cost, not the consumer cost unless otherwise specified. Like “this is 30% cheaper on my food stamps”.