I agree that $3000 will get you a very good bike with good components that will last a long time. Although, $2000 is quite doable as well. If you get much below $1000 quality becomes suspect and the bike might be a hassle to maintain. I would recommend considering a "Cyclocross" or Randonneur style bike. They ride well on pavement or "gentle" offroad (dirt or gravel roads). Since you are in CA you might check out Rivendell bikes. http://www.rivbike.com/

As a biker, runner and a geek, this post made my day. My unsolicited bike advice: don't get a tandem do get Anne her own bike.