you can use ww.searchtempest.com to look at multiple craigslist regions. "weber" and "webber" usually return the greatest number of hits. Be patient, it took 6 months for my WSM to show up on Craigslist...I bought it that very night. I would guess that most people with a weber are either using it or thinking that they might at this time of year. If you can't wait, a new one touch silver is only about $100... not bad for a piece of equipment that can last 30 - 40 years even with regular use.
18.5 WSM, Green Weber Genesis320, Cast iron firepit(w/grill), and a Copper Weber 22" OTS