This app was mentioned in 3 comments, with an average of 0.67 upvotes
Shameless plug, but I'm not only a collector on here but an Android developer...I recently published an app that can help you find these deals on Craigslist as soon as they're posted. No need to check on your own. ;-)
https://play.google.com/store/apps/details?id=com.raptureinvenice.hawkeye
I've had this application installed on my phone for a few weeks. It gives an alert whenever "sega" or "nintendo" shows up in a new craigslist advertisement nearby. My beef with it is that I can't/don't know how to add multiple locations... I'm right in between two of them. Anyway, usually it gives me updates about people selling cars or other stuff I don't want, but today it worked out pretty good. :P