[thaumasiotes]

> In most of the US that’d be illegal (unless the four pack was itself a separate product instead of four individual ones).

Really? Because KFC does this all the time with a la carte biscuits. The per-item rate is higher if you buy four (as advertised on the menu) than if you were to buy one four times in a row.

[bombcar]

If it's part of some combo it can fly, but if it's literally "order 4 and get charged more than ordering 1 four times" you can probably report them to the Commerce Department.