Design area pricing

Hi,

I asked for a feature request before purchasing the plugin and support told me that this feature was available. I guess this feature is not available or I couldn't find it. If this feature is not available, I would like to request a feature.

My request: My customers should be charged according to the area covered by the design they made. I should be able to set a price as 1inch²=$0.10. For example, if the user made a 10.5inchx9.7inch design, they should pay 10.5x9.7x0.10=$10.185.

Best regards.