Just a little Idea.
Is it possible, that you create an option in your tool that changes the basic price of an item,too?
Means: You have the price Ratio in your tool, and next to this, it would be easier for all, if there would be a option to change the basic price.
And yes, i have no experience in coding tools.
Don't know if you do it and dont know if it`s usefull, but here`s an script to change the basic price.
Code:
use arcadia
update dbo.itemresource
set price = Here_Price
where ID = Here_Item_ID