On the item section, there's only adding rate (like selling price).
Base on the cost or purchasing would be great feature if we can enter the cost price, setup the markup or margin and having group items. (like assembly line)
Also if you can add barcode scanning feature and or S/N with barcode would be great.
Right now I can only enter the selling price, and it's hard to remember how much was my cost or average cost and each customer can have different level for pricing.
In fact I am doing this whit Excel and it's simple formula in excel.