On average, listings lease in the $10's per square foot per year. The Santee submarket is going through a decrease in rates. In the last 3 months, the median rate fell $2 per sqft per year. That's a 10% decline in rent.
Compared to the rest of the San Diego market, the Santee region has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 3 listings have been listed, which means new listings most likley are going fast. 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 1,000 sqft. Most buildings in this area are approximately 2 stories. Most buildings in this market were built in 1972 and are Class C.