Price List in Ofbiz - Robust?

[ja...@productive1.com]

Team - I have always heard that pricing in Ofbiz is pretty robust and I
am trying to figure out how to make Ofbiz handle the following scenario

Let's say I have a suggested retail price of $20 in my price list, $10
Costs, and Margin of 30% (this needs to be able to change frequently)

I want to create a price rule that says the following:

For ALL items for a given OEM ID (listed on the main catalog page)
I want the following calculation

Retail-((Retail-Cost)*Margin)
or 

20-((20-10)x.3)= 18

Where in price rules can you create calculations like this?  Also are
these prices actually stored in the database?

Any help is really appreciated.

Thanks,

James