Compared to the rest of the Metropolitan Los Angeles market, the Montclair region has more expensive rates, and you'll need to make a great offer to be in this hot region.
In the last 90 days, 2 listings have been listed, which means new availabilities are probably going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 130 sqft. Most buildings in this market were built in 1979 and are Class B.