Compared to the rest of the San Diego market, the La Mesa region has higher rates, and you'll have to negotiate above asking rent to be in this hot submarket.
In the last 90 days, 10 listings have been posted online, which means new availabilities most likley are going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,790 sqft. Most properties in this area are close to 2 stories. Most buildings in this market were built in 1979 and are Class C.