On average, listings lease in the $20's per square foot per year. The Apple Valley submarket is going through a an increase in rates. In the last 3 months, the median rate went up $5 per sqft per year. That's a 30% increase in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Apple Valley submarket has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 5 listings have been listed, which means office spaces might be leasing quickly. 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.
The standard measurement for office space in this area is around 2,100 sqft. Most properties in this area are close to 2 floors. Most buildings in this market were built in 1989 and are Class B.