They're not thinking this through.
The rich (people with disposable income) are more likely to purchase a good as part and parcel of a service. Let's say a rich man wants to keep his lawn in shape. He doesn't have time to maintain it himself so he hires ABC lawn and garden to make it look good. Well, ABC L&G looks over his lawn and property and makes recommendations about landscaping and agrees to maintain it once a week, with the owner taking care of watering the plants daily.
ABC L&G then makes the necessary purchases at the local nursery, sod grower, garden center, and perhaps quarry before returning to install the agreed upon landscaping. All of the items were billed at cost on ABC L&G's invoice, and perhaps plus, to the rich man, he bought it. It would look like he didn't pay a dime in sales tax when he indirectly paid for all of it.
The same thing if he hires a maid service who provides all the cleaning solutions it will use.
DUmmies can't think past the first layer.