Creating an item with advanced cost price

Hi, I'm fairly new to AX 2012, and I'm trying to create a configurable product with the new product configurator.

I want the cost price to be determined by an equation like this: PRICE = constant + width * widthConstant + height * heightConstant

The width and height are in millimeters, and the range can go from 600 - 2000 in each dimension, so there's no way I can predefine the cost price of different combinations.

I figure I can accomplish what I want by having three items, for every configurable product:

itemConstant, having a cost price equal to "constant" in the equation, quantity set to 1
itemWidthConstant, having a cost price equal to "widthConstant" in the equation, quantity set to attribute "Width"
itemHeightConstant, having a cost price equal to "heightConstant" in the equation, quantity set to attribute "Height"

Then I can add them to the configuration model's BOM.

However, this seems like a lot of maintainance to me. Isn't there some way to set up an equation using the "height" and "width" dimension to calculate a cost price?