Most listings are in the $20's per square foot per year. The San Marino submarket is seeing a decrease in rates. In the last 3 months, the median rate decreased $12 per sqft per year. That's a 35% decrease in rent.
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 undervalued submarket.
In the last 90 days, 1 listings have come on the market, which means spaces most likley are leasing quickly. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,000 sqft. Most properties in this market are around 2 floors. Most buildings in this region were built in 1961 and are Class C.