http://sandiego.craigslist.org/csd/spo/4404330167.html
This ad on craigslist for a Wilderness Systems tarpon 120 for 300$
I own a tarpon 160 (pre-2009 model) and absolutely love the thing!
I'm a light weight guy so it's difficult to paddle fast and cover ground quickly but for the most part it is extremely stable and these kayaks are great for converting into a fish slayers!