Does Stocky app auto-update product cost in the Product Window?

I’m using stocky app to generate the purchase orders. But I have noticed that the cost per product is not automatically updated in the Product Window. My question is if in addition to generating the purchase order I have to go to the Product Window and enter the cost manually. And if so, what happens if I reorder the same product at different cost, how the application adjusts the cost of the product?