Using 'variables' to sell products at different prices

Q: I want to use Jigoshop to set up the supply-only side of my business. We sell artificial grass so I would need the variables feature to either calculate a final price using a set unit cost, or failing that, allow me to enter full prices manually but creating lots of attributes and variables.

The grass we sell can be purchased in either 2m or 4m wide rolls. My issue is that customers then need to be able to select the length they would like (to the nearest full meter). So the price will vary dramatically depending on whether someone has selected 2m or 4m width as it is sold on cost per m2 basis.

A: You would set it up like following:

Attribute #1: Name: Width Options: 2m, 4m
Attribute #2: Name: Length Options: Range of options in 1m increments

The final prices for the length of a 2 m and 4 m roll would be separate. In Jigoshop, variations are made manually in the following manner - if I sell T-Shirts in Red and Blue and in L and S sizes variations would be:

Red+L= 5.00$
Red+S= 3.00$
Blue+L= 10.00$
Blue+S= 7.00$