[DSMan195276]

I disagree that people are incapable, I think a large portion just don't care all that much. Frankly I certainly fall into that category for lots of things - I'm more concerned with getting a reasonable amount (and not wasting tons of time in the store) than the exact cheapest price, especially when the difference usually isn't that drastic in the end. Going with your example, I buy a 12 pack because I don't drink pop that often and really don't have room to store a 24 pack, so saving a dollar or two just doesn't justify it for me. Where-as for other products that I do get a lot of I take the time to make sure I'm getting a good deal.

I will readily say that the above is a luxury that not everybody has, but then buying the best per oz price is a luxury not everybody has either. Certainly there are oddball cases like you pointed out, but typically the larger items have a better per oz pricing and not everybody can afford the higher upfront price even if the per item price is less.