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 decreased $2 per sqft per year. That's a 6% decline in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Santa Ana submarket has lower rates, so you should have no trouble finding a great deal in this undervalued 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 need to consider the implications of signing a direct lease with the building. There aren't many listings below 2,000 square feet on the market, 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 buildings in this region are around 2 stories. Most buildings in this region were built in 1982 and are Class B.