If you want a downtown area and you want sort of an old-fashioned town (meaning some rich, some avg, some poor, some conservatives, some liberals) that’s concord. Ports out of your range, manch and Nashua depending on your own background and expectations you might be a little uncomfortable sending your son to the public schools. If you want quaint old NE small town but lacking diversity maybe Amherst, Milford, Hopkinton. If you want relatively high-driving transient suburban-type get-ahead lifestyle but lacking diversity that’s Bedford (but tough to stay below $500-600k. Re-reading your post I’m thinking you should be comparing Keene with Concord. Keene is a little wealthier probably and there’s a small college.