Also just because something is in a larger size, it doesn’t always make the prices better. Once I was at Fred Meyer and the 1 pound bags of lentils were $1.50 but the two pound bags were $4.00. They were charging more for larger handling units.
You can trust nothing in grocery stores.
You're effectively running volume arbitrage to even out inefficiencies in seller's upstream suppliers.
Or, to put it another way, the seller's profits (margin*volume) can often be the same on smaller package (even for cheaper per weight unit) as larger package (for more expensive per weight unit).
They weren't impressed when I put in two orders of a single scoop....
I needed Q-Tips as I had finally run out of the box I bought years ago.
They had 350 Q-Tips in a box for $3.49. Ok, about 1 per penny.
They also had 500 Q-Tips in a box for $4.99. Practically the same price minus some infinitesimal rounding money.
I was about to reach for the 350 when I noticed they also had a 650 Q-Tip box for... $4.99.
And they were not on sale. None of them were. This was their flat Q-Tip pricing.
I would have guessed that the price should have been $6.49 to keep with the trend, but my guess would have been wronger than using "wronger" in a sentence where you should have used "more wrong" instead.