Most listings are in the $30's per square foot per year. The La Mesa submarket is going through a decline in rates. In the last 3 months, the median rate decreased $1 per sqft per year. That's a 2% decline in rent.
Compared to the rest of the San Diego market, the La Mesa submarket has smaller rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 11 listings have been listed, which means new availabilities 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 850 sqft. Most properties in this market are approximately 2 stories. Most buildings in this market were built in 1979 and are Class C.