The typical asking rate per listing is in the $20's per square foot per year. The Castaic submarket is going through a a boost in rates. In the last 3 months, the median rate rose $24 per sqft per year. That's a Inf% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Castaic submarket has smaller rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 2 listings have been listed, which means new listings most likley are going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
Even though the median size is 4,950 sqft, there are still 0 office spaces below 2,000 sqft. Most buildings in this area were built in 2008 and are Class A.