To find a great deal, look to wine regions that are not as trendy, such as Lodi, CA.

If you want cheap and good:
Peirano Estate Vineyards, Lodi, CA
They have a $2/bottle Zinfandel that you can only buy by-the-case at the winery itself. Lodi excels in Zin and even though this bottle is not as complex as an old vine zin, a case costs less than most single bottles! Who needs 2-buck Chuck. This wine actually tastes good. No burn your nose alcohol like bad cheap wines.

Michael-David Vineyards - Can find their wines at Cost-Plus and Costco as well. I've loved all their reds and they are very well priced. around $15/bottle, depending on the wine

Jewel Collection, Lodi, CA
This winemaker believes that no wine should cost more than $10 a bottle and that's how he sells his wine.