Good points by 4W4 & s.a.h.
IMO, 104,000 miles still has a lot of life left (~70,000 miles before a $1000 simple rebuild). I'm not up on 4-bangers, but if you intend to do much hill/rock climbing or off-roading, then pass this one up. There's always
another CJ with a V6, 6-cyl, or V8! But then again, you'll likely be faced with having to rebuild that engine as well. Can you do that sort of thing yourself?
My first impression on the details you provided were that $2000 is pretty good. I shelled out $2200 for my '71, but to be honest, I've been surprised as often as I have been disappointed (found out I've got overdrive and Levi Strauss edition seats!
Test drive it and let us know how it goes, that's the most important. Note ease of drive/shift. Get underneath and inspect for rust on frame, body mounts, floorboards, etc. If you have ice in your veins, do your best to chip away at the seller by convincing him/her that the asking price is unsubstantiated, and offer maybe $1450 and then immediately pull out your checkbook. Let the wheelin' and dealin' begin!!!