On average, listings lease in the $10's per square foot per year. The Santee region is seeing a decrease in rates. In the last 3 months, the median rate decreased $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 lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 2 listings have been listed, which means spaces 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 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 properties in this area are close to 2 stories. Most buildings in this area were built in 1972 and are Class C.