The early Cal models are some of my favorites, so I certainly think the 30-2 is a good boat to buy. You need to look closely at whether this particular one is worth $5K or anything at all. The cosmetics are very poor. If the engine runs and mast/rigging/sails are in satisfactory condition, it might be worth a few thousand as is. Then consider the repairs needed. Would you be able and willing to do the repairs yourself? If no, move on because the cost of yard work would quickly put you upside down financially in a boat like this. If the major components are operable, and you can do repairs, offer a few thousand and see.
If your offer is accepted, have a survey to find if the deck or cabin sole, or anything else needs repair. Have an engine mechanic survey the engine. If you feel very comfortable that you can do all necessary repairs, close the deal and start your project...otherwise walk away.
If you are careful you still run a big risk of ending up spending more than the boat will ever be worth, unless you are confortable sailing the nautical equivalent of a pigsty. Realize that new cushions, a sail or two, replacement instruments, new batteries, can quickly add up to $10K, and totally ignoring your time and sweat, it wont be hard for this boat to end up cosing as much or more than one like this, YachtWorld.com Boats and Yachts for Sale
= but never be as nice. I do believe that the surest path to a boat bargain is to pay the cost of just buying one the way you want it, if you need to take a 10 year loan to do so, you still make out in the end. This board is well populated with threads started by buyers of project boats, subsequently populated with periodic stories of $$ surprises, and then stopping as the owner decides not to talk about it anymore, or quits boating.