Use case is: I have products that have different prices from different suppliers. Maintaining several pricebooks is too complicated and we would need multiple pricebooks for Opty and orders. So we created a custom object named supplierprice with a lookup to product and supplier (type of account) and the price field.
Now I need from line item selections to show a field that shows the price based on the product and line item selection. After insert/update triggers will show it once it is inserted, I need to show it before, while user is entering quantity.
Is there a way to show a formula field or similar, that queries data based on selection changes?