Add (Add to inventory screen) to restock products
Wholesale purchases are normally a outer size pack and would be handy for when a product price increases but cant add cost until inventory depleted.
On this screen you would see all products with stock management, then click an + symbol
i bought a dozen apples for £3 = 25p cost
Then my suppliers price goes up to £3.20 a dozen. =£0.266p
Anyway of being able to accurately track cost of batches.