casbboy
The purchase price is used within Purchase Orders. From there, when you add an item, the price shown is the Purchase Price and you can change it and Update the original product's PP from there with the corresponding button.
More usages for the purchase price will come in future ATUM add-ons.
But, if you feel a waste of time, just don't use it. It's not necessary.
Best Regards,
Salva.