Most listings are in the $20's per square foot per year. The Santa Ana submarket is going through a decrease in rates. In the last 3 months, the median rate fell $2 per sqft per year. That's a 6% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Santa Ana region has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 146 listings have been made available, so you'll want to check back regularly for new listings. About 3% of the listings in the Santa Ana are subleases, so you will probably have to focus your search on direct office leases. 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 2,150 sqft. Most properties in this market are close to 2 stories. Most buildings in this market were built in 1982 and are Class B.