Here I thought that I was the only one who checked the unit prices of products that I was buying! I check unit prices all the time with my calculator that I carry in my purse. I like to get my money's worth and am very frugal when buying, so I check the unit prices often. I love Safeway's $5 Fridays where I just bought 2 two pound bags of Ore Ida's frozen french fries for $5! I save a lot so I go early to get items before they run out like 30 oz. of Safeway coffee for just $5 when it's on sale for the $5 Friday's, so far.
I've been trying to pay more attention to the per unit price these days, in particular when I am buying stuff such as fresh meats. I recently found a small corner market near me which was selling 10lb bags of fresh chicken breasts for only $12.99 - so that's about a $1.30 per pound, which was far cheaper than what the other grocery stores were selling chicken breast for. So of course I snapped it up right away. Normally fresh chicken breast would cost me well over $2 per pound elsewhere. However, sometimes the per unit price can be a bit misleading. For one thing, if you're buying cuts of meat that have lots of fat, skin and bones, that you will otherwise probably be discarding or not consuming, that's part of the weight as well. Another instance where I came across the price per unit being a bit misleading, was when I was looking at two different brands of frozen meatballs. One was 20 cents per ounce, while the other was 23 cents per ounce, which didn't seem like much of a difference, but the actual total cost difference between both products was $3.99 vs. $7.25. Granted the later was a few ounces more in weight, but the total price difference was much more substantial overall than it looked per ounce.
Yes, I always calculate what's cheapest and what's the most expensive if the prodcuts don't differ much. Who would want to pay more for the same thing? I always try to save where I can. Even when something is on sale, it doesn't mean that it's the best option so you really have to be careful when shopping, that includes checking unit price, too!
I have checked the unit price of an item to decide if I was getting a good or would it be a better price purchase if I got a larger size. I also take into consideration if the larger size would get used and not thrown out, if I have to throw some of the item away because I did not get it used soon enough it would not be a good deal. I should purchase the smaller size to avoid waste.