[londons_explore]

I want to know why these places don't simply dramatically drop the accuracy requirement.

Rather than giving itemized receipts, give just a total dollar value. Then just make sure that most customers are charged within 10% of the correct amount.

Only if the customer requests and itemized receipt, then go watch the video and generate them one. But after a while most customers won't request it, and that means you can just guess at a dollar amount and as long as you're close-ish (which should be easy based on weight and past purchase history), that's fine.

[leroy-is-here]

The problem is taxes. Different items can be taxed differently. Itemized receipts are a must from the get-go unless you want to explain to the government that you underpaid them because you charge within a 10% error-margin.