Compared to the rest of the San Diego market, the El Cajon region has lower rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 15 listings have been made available, which means new availabilities are probably 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 1,500 sqft. Most properties in this area are approximately 2 floors. Most buildings in this area were built in 1977 and are Class B.