Display Formula Data
In the Auction section the "Minimum Price"/"Maximum Price" when the user presses the "okay" button you validate the formula and then display the current results of the formula so the user has an idea of the results of that box. Then down the list add a box that show the range based on the specified data. DO NOT run to the auctionDB and try to determine the spot price for it at that moment, just give an visible idea of the result.
You can look at the tooltip of the item and get the same information.
Okay was thinking about this, problem is that you could be dealing with 1000 items. How about start with the first item in the items list for the pricing data, obviously you would have to have specified somewhere on the window that it is using x item to generate the ... then you would have to display the icon and be able to hover over it and see the data for ease of use. Guess you could display all the source data when the hover over it at the same time.