Add the 'purchase' field to the standard 'items' report, therefore listing all of the fields that are included when adding an item to the available inventory.
"Report data fields"
It would be really useful to be able to see the purchase price of items on the items listing, as well as the sale price.
The simplest would be to add the purchase price to the existing report of Items which currently only shows the sale price.
An enhancement could be to select from a dropdown which items to list on the report, and which attributes (sale price ex gst, inc gst, buy price inc/ex gst).
And if we had inventory (why don't we?) it could list items in stock too.