Most listings are in the $20's per square foot per year. The Tustin submarket is going through a decrease in rates. In the last 3 months, the median rate decreased $5 per sqft per year. That's a 15% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Tustin submarket has less expensive rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 27 listings have been listed, which means new listings might be 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 1,160 sqft. Most buildings in this area are approximately 2 stories. Most buildings in this area were built in 1980 and are Class B.