Product cost rules

[Jennifer Weston]

I'm trying to figure out how to define product cost rules for  
products. It looks like I may be able to set up something with  
ProductPriceRule, ProductPriceCond, and ProductPriceAction, similar to  
how I have price breaks for the same products. The problem I'm running  
into is how to make a distinction between the price rules for our  
customers and price rules for our company's purchase orders going to  
our vendors.

Does anyone have experience with setting up rules for product costs  
for use with purchase orders?