Selling Price is calculated from Unit Cost + Shipping + Duty using the category GP%. All costs are converted to USD (base currency) regardless of GRN currency — the ≈ USD column shows the converted value used for selling price and stock valuation. When invoicing in ZMW, ZAR, ZIG or AED, the USD selling price is automatically converted at the current exchange rate. Selling price only updates if the new price is higher than the current price. Untick "Apply" to skip price changes for a line.