It is incredibly difficult to sustainably run a winery in California. The margins are often negative without operating at a large scale, which is part of why the industry has consolidated heavily over the past few decades.

Often times, wealthy people buy wineries as a hobby to dabble in, but end up selling and calling it a day before it drains their cash. If you want to buy wine for cheap that is made in California, buy mass-market wine.

Smaller brands are generally expensive because that price is necessary to sustain operations, but most of the time that fails, and the owners end up selling.