I've had some moderate success selling mid- and high-end bikes on Craigslist. Granted this year is a bit unusual; you could sell a tricycle for 4 figures, but even so how you present on Craigslist matters. I'm of the opinion that a well presented bike can easily fetch a significant premium over a poorly presented bike.
On the plus side it turns out that there's not a whole lot of competition. In my market (Portland), here's what you're up against for bikes above $2500:
|Would You Pay $6000 For This?|