When I worked at HP years ago and had more manageable time, I would do my morning craigslist search for BMW stuff, cars and parts, when I saw something I wanted I called immediately and if they answered I told them I was on my way. I would leave work and usually be there within 20-30 minutes. I bought a '73 3.0cs parts car on a Saturday morning in town, was the first one to call and left five minutes later in a pouring rain storm to get to the car. Bought it as soon as I walked up and he said he already have about five or six other people waiting for him to get back to them. It is really really hard to get a good deal on craigslist or online classifieds if it seems like a good deal in the ad.
Now I force myself NOT to look on craigslist.