Supplier invoice PDFs to possible duplicate invoices, unit-price changes by item and a spend report — every figure checked by code (up to 500 invoices)

Upload up to 500 supplier invoice PDFs, loose or in ZIP files, and get back the points to check in them, worked out by code: possible duplicate invoices, unit-price changes by item at the threshold you choose, arithmetic differences on text PDFs, each supplier's payment terms, and your spend by supplier and month.