Retailers have recognized that shoppers caught on to the concept that bulk priced items are cheaper than smaller packages. They've began to flip that concept on its head. I ran into this today when i found the smaller bottle of cumin to be cheaper per ounce than the large bottle. I expect that they've done the about the same thing here where people will expect the bottom shelf stuff to be cheaper especially with the novelty of it being packaged in a flimsy milk bottle.

That's pretty cheap for 4L, considering the provincial taxes