Craigslist (and a yardsale) worked for our family, but it depends on how active that is in your area and how good people are about getting back to you. We ended up with a used Specialized, Kona, and Trek (and a Schwinn) for $360 total for 4 bikes. The adult bikes were in the $400 range when new, so we feel we did pretty well. The Kona needed a little more work, but it's a good quality bike from what I've read. We'll see how we like family biking first and then decide whether we need/want to upgrade. It's kind of a nice feeling to put a used bike back on the road, too.