I sell cigarettes in both cartons or by packs.  Same product, but have different barcodes and prices.

10 packs of cigarette comes packaged in one carton.  Whenever I sell all 10 packs of cigarette that I broke out of carton, I'd open another carton and sell. However, sometimes a customer would buy the whole carton.

I would buy the cigarettes by the cartons and keep it stocked as carton, unless as mentioned above I'd have to break them out and sell as pack.

How can I adjust the inventory, so whenever I sell 10packs it would deduct 1 carton off of my inventory?

I thought about just ringing up 10 packs of cigarette when selling a carton, but carton price isn't 10 time the pack.  There would be a different discounts depending on the brand.  Also it would be so much easier to just scan the barcode on the carton, instead of (scan pack, times it ten, apply discount....)

Anyone using square at retailer selling cigarettes have any good suggestions?