If I change a product's price, does the cart update?
The cart shows the price at the moment the item was added. When you tap checkout confirm, DingPOS re-queries the latest price of every item — if anything changed, it alerts you with the updated prices before proceeding.
Promotions are also re-evaluated from scratch at confirmation. If the total, tax, or any discount amount changes as a result, a change summary is shown and you must confirm again — so the amount you see is exactly the amount recorded.