On average, listings lease in the $10's per square foot per year. The Lemon Grove submarket is going through a a boost in rates. In the last 3 months, the median rate increased $14 per sqft per year.
Compared to the rest of the San Diego market, the Lemon Grove submarket has less expensive rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 4 listings have been posted online, which means spaces 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 730 sqft. Most buildings in this market are around 2 stories. Most buildings in this market were built in 1985 and are Class Class C.