Napa Cab is always going to be expensive, but I also haven't found any other regions that will give you the same flavor profiles as a good substitute. This is why I tend to focus on regions like Rhone, Loire, Italy, and Bordeaux (which is getting tricky for values). And, honestly, one of the reasons I'm getting into Bourbon.
I've found quite a few Pinots I enjoy around $25, my company also buys/sells wine collections so we get lots of odds/ends from those that usually keep my curiosity occupied.
That said, I got an email today for a bottle of 1970 Chateau Palmer for $280, I'm quite tempted. One of the best wines I've ever had.