Change Affiliate Payouts based on which level in Pro Sites?

I have Pro Sites and Affiliates installed. With Pro Sites, I have a Silver and Gold membership defined. Silver is $5 a month, gold is $10.

Is there a way for Affiliates to pay out based on which membership level the customer ends up buying? Either that, or instead of a dollar amount, pay a percentage out?

If it were paid out at a percentage, that would make things really nice (coupon codes and such).