On average, listings lease in the $10's per square foot per year. The Lakeside submarket is going through a decrease in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 8% decline in rent.
Compared to the rest of the San Diego market, the Lakeside region has smaller rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 4 listings have been listed, which means leases 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 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 610 sqft.