On average, listings lease in the $20's per square foot per year. The Fullerton region is going through a decline in rates. In the last 3 months, the median rate decreased $2 per sqft per year. That's a 6% decline in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Fullerton submarket has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 14 listings have been posted online, which means listings might be leasing quickly. You'll want to be prepared to make an offer immediately. About 307% of the listings in the Fullerton 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 1,480 sqft. Most properties in this area are approximately 2 stories. Most buildings in this market were built in 1973 and are Class B.