Most listings are in the $20's per square foot per year. The Alhambra region is going through a a boost in rates. In the last 3 months, the median rate increased $9 per sqft per year. That's a 44% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Alhambra submarket has less expensive rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 5 listings have been made available, which means new listings most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. 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 990 sqft. Most properties in this region are approximately 3 floors. Most buildings in this area were built in 1985 and are Class B.