How long should a starter last?

This general question is a good one, but even with more specifics, only a general answer can be provided. A starter will last "several years" under normal use. That's about it. Note that a number of auto parts outfits warranty a starter for a long, long time if you pay a bit "extra" for it. They expect replacement starters to last pretty much for the life of the car - while you have it. The warranty isn't transferable. They're betting you'll get rid of the vehicle before their starter fails. And they've done their homework. They make money by "guessing" correctly. Starters are generally pretty tough. Ten years isn't a long time for a starter to last under normal use. A properly maintained engine in a "normally" operated car won't place an inordinate burden on the starter, so you should get some good "mileage" out of one.