Well your best bet in the bay area is to follow craigslist.org daily.Go to the for sale area and do a search for arcade.
I have followed it daily for about three month and ended up with I consider the find of the decade on craigslist.I was able to get a 4 player gi-joe konami cabinet with 25 inch monitor for a wopping 100.00 bucks.Everything worked ,just had to do a little work on the monitor.
Since purchasing this i have continued to follow craigslist daily and the closest deal to this was around 250-400 bucks.If you see a deal that looks good awesome to you dont wait ,call or email immiediatly.The person who sold me mine had over twenty emails in the first day.Luckily I was first and told him I have a truck ,what day do you want me to pick it up?
Hope this helps,good luck.,Will