MarketPress: Different Commission Percentages for Different Products

In MarketPress, I am able to set commissions to charge 'store owners" to add a product:

Use our advanced Adaptive Payments gateway - Take a predetermined percentage fee of all store sales on your network! Completely automated and invisible to store customers. You can also allow Pro blogs to opt out of this by using a different gateway.

I want to charge different commissions for different types of products automatically. Is it possible to create different categories of product postings (i.e., electronics, clothing) and then pre-set different commissions for different products?

if this requires custom work, how would you go about doing this?