The first step is a doozy

I am often bothered by the cost of shipping for orders, especially on smaller orders, since a single bottle can carry a shipping cost around $7 or more, depending on distance to customer. Of course, my figures I am about to mention are not adjusted for the coming rate increase from the post office, and is the rate for them to be shipped to where I live, the same town they would be shipped from, so it is really the minimum values for the test item, but....

USPS standard shipping (to the same town I ship from)

1 bottle $6.61
2 bottles $6.61
3 bottles $7.01
4 bottles $7.38
5 bottles $7.71
10 bottles $8.63
25 bottles $10.37

Now, being fair, the store offers free standard shipping once you hit $100, most likely one would hit that before they hit 25 bottles. (With some being upwards of $10, and some much higher due in tomorrow, it might only be a few bottles to hit that point, but with mini bottles, it could take a whole lot more.)

The point is, rather, that the first bottle is the most expensive to ship, one bottle in this demo is about $7 to ship, but less than 90 cents per bottle when 10 are bought at the same time. For fun, I looked up the cost to ship 250 bottles, and came up with $63.08. Now, granted, if someone ordered that and it was only going across town, it would be that, elsewhere would be a bit more. Still, assuming free shipping had not been triggered, that is around 25 cents per bottle. Talk about economy of scale.