+1 on this assessment of the Bay Area. I don't have any stats to verify this but it's my impression that two things distinguish our local CL: high average price and sheer volume.

Around here, any POS with two wheels that spin will regularly sell for $200+. You almost never see a complete steel road bike listed for less than $150. I guess there's enough demand for even beater bikes that no one has to sell a bike for any less. I see other guys from different parts of the US posting on here about snagging a medium- or high-quality steel ride for 20 or 30 bucks and I just laugh (so that I don't cry). You can hardly buy a seatpost or a stem for that much in my neck of the woods.

The rate of new posts here is nothing short of amazing. I'd say on an average day, we see 2-3 posts every minute. The upside to all this volume of course is a wide selection. If you're willing to wade through all the crap you'll find that there are some gems out there almost every day.