My brother and I picked up a 1967 Cal 20 for $600. It had sat on barrels for about 8 years, but we restored it over a three month period and learned a great deal. We posted sets of pictures throughout the process, and here’s a link to the final set (maiden sail):
The funny thing about Cal 20s is that they have a real following. There’s an active fleet that races locally, and serious members of the local sailing community own and sail them. They hit a “sweet spot” of being affordable, easy to maintain, fun to sail, and are relatively seaworthy for a 20 foot boat. Down in California they are sailed to Catalina Island on a regular basis, and one was sailed to Hawaii.
Anyway, we love the boat and even sail it in the winter. They are available in the $2k to $5k range in much better shape than the one we started with.