The typical asking rate per listing is in the $20's per square foot per year. The Fullerton submarket is going through a decline in rates. In the last 3 months, the median rate fell $4 per sqft per year. That's a 13% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Fullerton region has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 28 listings have been listed, which means listings are probably 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 800 sqft. Most buildings in this market are close to 2 stories. Most buildings in this market were built in 1975 and are Class B.