I've just finished pulling in the Spiceworks purchases into Lansweeper and attached is my writeup on how to do this. 9 pages in Word with screenshots.
Basically you export from Spiceworks, changing one export field (Total Price for Price) and match those columns to Lansweepers Ticket Import function.
Attached are screenshots of Closed purchases in the "Helpdesk ticketing system", a final Purchasing Dashboard screenshot and a guide to explain the process.