# Best formula for price depending on amount [closed]

What is the best formula of price of the product depending on amount. I mean "best" in psychological, marketing, stock rotation, profit maximizing, etc sense (any of them or all together, if possible).

Say, I often see that prices on Coca Cola bottles growing not as fast as volume of them.

I sure there is the best formula, invented by psychologists or derived empirically then proved in use.

• Feel free to edit the question, because English is not my primary langauage. Mar 4 '16 at 9:26

There is no "best" car design, there isn't a formula to design the fastest airplane with total weight $x$ and there is no easy formula that will give you the best price in general situations.