The typical asking rate per listing is in the $10's per square foot per year. The Santee region is going through a decrease in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 15% decline in rent.
Compared to the rest of the San Diego market, the Santee submarket has less expensive rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 5 listings have come on the market, which means spaces might be 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 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 1,390 sqft. Most buildings in this area are close to 2 stories. Most buildings in this area were built in 1972 and are Class C.