Compared to the rest of the Metropolitan Los Angeles market, the Tustin region has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 27 listings have been made available, which means new availabilities 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,280 sqft. Most properties in this market are close to 2 stories. Most buildings in this market were built in 1981 and are Class B.