I never saw this combination before, so I made it with an EV3 education set. I intend to present it for the "out of the box" challenge. At the beginning, the machine looks at the articles on the conveyor belt thanks to the color of each article. Meanwhile it displays the name of the different articles on the screen with their price and the total amount. The buyer puts a beam after all his things to stop the conveyor belt. He can then put coins that the machine recognizes thanks to their size. He repeats these actions until the total amount is reached. I added some sound effects while scanning articles or confirming the purchase. It remains only to make a machine which gives the buyer his change or which detects if someone pass without pay (and shoots at him in that case ;-)) but I can't do that with only one set :-(.
I'm french, so the text is in french and the devise is €.