RFID still costs several cents per sensor. At suparmarkets, this is a non-starter, but for some retailers, like Uniqlo, it's acceptable.

You would think that overpriced concessions would be a great place for this because it can be very fast and accurate but I think this would require the food handler to make sure to use a different tray or container for each differently priced item, etc. And there may just be enough items that would be hard to affix an RFID to (metal can, etc) that would make it unfeasible.