I sometimes fall into the trap of thinking along these lines -- "woo hoo! free shipping! That must be a good deal!" Then I have to remind myself to do all of the calculations, to see if it really is the best deal.
You've probably seen this on Amazon: you can buy the same product in different amounts and from different sellers, and at different price points, some with minimal shipping costs, some with hefty shipping fees.
A supplement that I use can be bought 1 container at a time, under the "spend $35, and get free shipping" fulfilled by Amazon. Or, it can be bought in a 2-pack, from an authorized seller, for less per bottle, but with a small shipping charge. That shipping charge was a stumbling block for me, this past week. I kept thinking, "oooh I want to get that free shipping". However, overall, including shipping, it was cheaper per bottle than buying it, fulfilled by Amazon, with the free shipping bonus.
It took me most of the week to finally get it through my head that the second method would make the most dollars-and-cents sense. I was still able to take advantage of Amazon's free shipping, but on a different order, altogether.
And another reminder for myself (and maybe you, too), the biggest package is not always the cheapest. When looking at buying unflavored gelatin in food service containers, it was cheapest per unit to buy gelatin 2 containers at a time, and not 3 or 4 at a time.
I also discovered this to be true when ordering replacement filters for our refrigerator. Buying a 3-pack was less expensive per filter than a 6-pack. Go figure! But I'm glad to not have to commit to (and store) more than a 3-pack for the time being.
Gotta remind myself to always do the math!
