So I’m looking for a tool that can tell me the total cost of things I buy. Like if I buy item A for 1,20€, item B for 5,60€ and item C for 10€, it tells me how much the things I’m buying cost, which would be 16,80€ in this case.
I tried looking it up, but apparently ddg is once again incapable of showing any relevant results.
This seems like a classic use case for a spreadsheet. A good free one is Libre Office (or if you really want an online one, google sheets).
Put your items/prices into a pair of columns, and put a SUM function in the field below the prices to show the total.