Here's two pieces of savvy-shopper money-saving advice you hear all the time: “Check the unit prices” and “Bigger is usually better.”
The first rule is most important, because it shows when the second rule doesn't apply.
Case in point: I took these photos on June 29 while shopping for over-the-counter allergy meds at a Target store in northern Virginia.
The generic/store-brand version of what I wanted came in two sizes: a 14-pill bottle for $5.19 plus tax, or 30 pills for $13.29 and tax.
Confession: as a frugal shopper, I initially reached for the 30-count bottle because I know “Bigger is usually better,” but fortunately, I also remembered to “check the unit prices” and (with help from the calculator I always carry while shopping) quickly determined that 14 pills for $5.19 comes out to just over 37 cents per pill, whereas 30 pills at $13.29 costs 44.3 cents each.
The bigger size usually offers the best price, but not this time. I bought two bottles of 14 and, despite having only 28 pills rather than 30, still saved money compared to what I'd've spent had I simply grabbed the largest-size generic offered for sale.