In order to understand how to set the pricing of your multiplers, it will be necessary to understand exactly how the cost associated with the Width x Height Calculator is being reached. Please reference the equation and breakdowns below.
Here is a breakdown of how this works:
MP = This is the main product price. Which will be constant.
A = Area
Q = Quantity Multiplier.
M = Multiplier Product Price. (This is the price of the product that you added onto the W x H calculator in our app for the upcharge amount)
QM = the total of your Quantity Multiplier x the Multiplier Product Price
T = Total
So your equation will look something like this:
MP = MP
A = W x H
QM = Q x M
T = MP + ( A x QM)