On Marketpress is it possible to have multiple commission fees?

I currently am building a Marketpress website for a client who is using PayPal Adaptive Payments, however one of the biggest things we need is the ability to charge different comission fees based on the type of product being sold on the marketplace.

Because of this I wanted to ask if it is possible to modify Marketpress to have three different percentage fields in the control panel, and then depending on the category a product falls under, we assess the appropriate fee.

Thanks in advance for any assistance,

Charles