If a few cells fail, the replacement is cheap... if the battery is actually designed in a way individual cells can be reached (physically) and replaced.
If the current state of vehicle repair is any indication the only people who will replace "a few cells" will have a shop located in a rough part of town, not speak english and will require you to pay cash and the HN crowd will deride them and their business model for the most part.
If a few cells fail, the replacement is cheap... if the battery is actually designed in a way individual cells can be reached (physically) and replaced.