now that you are at the brink of buying wine directly from the winery via the internet (a supreme court ruling was recently issued on thos) i'd say that you have loads of choices coming up.
I generally tend to hoover in the 20-30 range but in the 10-15 range i'd suggest some of Coppolas wines. Coppola's Rossi at $8 is a steal and works great with tomatoe based past dishes.
For pinots i've found a favourite in bergstrom (which i remember i picked up at $15) but this is hardly the wine that is easy to find. If you do find it, it's excellent.
For cheap but excellent cabs i'd suggest Ahlgren wines. he is a small grower in the santa cruz mountains and he makes an excellent cab in my opinion. Can only buy from the winery, i know of almost no shops who carries his wines (Wolfgang Puck serves his wine at his restaurant in silicon valley). http://www.ahlgrenvineyard.com/index.html
For those of you who love the california Zin's, this is just about as good as it gets. Tons of chocolate and spicy flavours creates this wonderful wine.
The merlot from ahlgren is so-so imho.
Dexter who runs this small family winery is retiring in december so in a few months there won't be any more of his great wines.
anyway, i have no affiliation with this winery other than i enjoy dexters wine making. And there are few of these family run wineries left in the world that makes really good wine.