How can I find the base price and price per unit?

Question

I have a table filled with retail prices for various width*height combinations. How can I approach to find the formula for this chart?

Answer 1

Your data consists of width values $w_i$, height values $h_j$ and retail prices $r_{ij}$.

We assume a function $$ r_{ij} = f(w_i, h_j) \, u + b $$ with unknown $f$. Entering four of the price rows (data) I get

This data seems to be linear with a kink for the last three widths. So it should be possible to interpolate.

But your question, how to assign a useful unit and base price, I can not answer.