Could you give us a little bit more information about your pricing?
Do you have a price list? Like a price per painting that you print for a museum?
Or is it more general like a price per page size and paper type etc?
You could make a price list that has two price fields "AffiliatePrice" or "CustomerPrice" And then get the appropriate price.
But I don't know enough about your situation to be able to make a detailed suggestion.