Most listings are in the $20's per square foot per year. The Mission Viejo submarket is going through a decrease in rates. In the last 3 months, the median rate decreased $19 per sqft per year. That's a 42% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Mission Viejo region has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 14 listings have been listed, which means spaces are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 100% of the office spaces in the Mission Viejo are subleases, so you might be able to find a shorter term or below market rent. 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 690 sqft. Most properties in this region are close to 2 stories. Most buildings in this market were built in 1988 and are Class B.