Most listings are in the $30's per square foot per year. The San Marino submarket is experiencing a a rise in rates. In the last 3 months, the median rate went up $36 per sqft per year.
Compared to the rest of the Metropolitan Los Angeles market, the San Marino region has less expensive rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 1 listings have come on the market, which means office spaces most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 100% of the available space in the San Marino are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 620 sqft. Most properties in this region are approximately 2 stories. Most buildings in this region were built in 1951 and are Class B.