How to keep the original value on a table after an override?

I have a table that displays the qty. entered by the user when they uploaded their spreadsheet. We want to show the user the alternative price for other quantities, so if they originally entered 80 they could see that if they change it to 100 the price may be cheaper and they can get a better deal. The stakeholders want the original quantity entered by the user to remain visible somewhere, so if they click on one of the radio buttons and the qty field updates with that selection but let's say minutes later they change their mind and want to revert to the original quantity how can we show them that?