Most listings are in the $10's per square foot per year. The Santee submarket is seeing a decline in rates. In the last 3 months, the median rate fell $2 per sqft per year. That's a 10% decrease 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 discounted submarket.
In the last 90 days, 3 listings have come on the market, which means new listings 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 posted, 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 region are approximately 2 floors. Most buildings in this region were built in 1972 and are Class C.