The typical asking rate per listing is in the $30's per square foot per year. The Vista submarket is going through a a rise in rates. In the last 3 months, the median rate went up $8 per sqft per year. That's a 36% increase in rent.
Compared to the rest of the San Diego market, the Vista region has smaller rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 55 listings have been posted online, so you'll want to check back regularly for new listings. 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 880 sqft. Most properties in this market are approximately 2 floors. Most buildings in this market were built in 1999 and are Class B.