Compared to the rest of the San Diego market, the El Cajon submarket has smaller rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 10 listings have been listed, which means listings 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 1,760 sqft. Most properties in this region are close to 2 stories. Most buildings in this area were built in 1978 and are Class B.