The typical asking rate per listing is in the $20's per square foot per year. The Costa Mesa submarket is going through a decline in rates. In the last 3 months, the median rate fell $6 per sqft per year. That's a 19% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Costa Mesa region has smaller rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 80 listings have been made available, so you'll want to check back regularly for new listings. About 3% of the available leases in the Costa Mesa 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 1,970 sqft. Most properties in this region are approximately 2 floors. Most buildings in this region were built in 1983 and are Class A.