Ability to track multiple input purchase prices and suppliers in input setup

Customers expressed the necessity to be able to have multiple purchase prices for their inputs, as they do not always buy from the same supplier and for the same price. As well, customers would like to track the companies they purchase their inputs from. This could easily be done by having a + option under the add input detail screen, where then you could pick the purchase price, purchased on date, and then pick a supplier.