Hi saucemania ,
You can track the different PP with our premium addon Multi Inventory (you have the option to have different inventories pre product) and maybe even better with Purchase Orders PRO. Our devs are working on a Purchase Price functions within the Export PRO addon as well.
The current stock value is possible to see in the ATUM Dashboard. You have to check the value at the end of the year as there is no function that actually allows you to go back in WooCommerce.
Hope this helps.
Pavel