On average, listings lease in the $30's per square foot per year. The California region is seeing a decline in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 3% decrease in rent.
In the last 90 days, 10133 listings have been made available, so you'll want to check back regularly for new listings. About 5% of the listings in the California 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,250 sqft. Most properties in this market are approximately 2 stories. Most buildings in this region were built in 1958 and are Class B.