The typical asking rate per listing is in the $10's per square foot per year. The Pomona region is seeing a decrease in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 14% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Pomona region has smaller rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 21 listings have been listed, which means new availabilities are probably going fast. You'll want to be prepared to make an offer immediately. About 10% of the listings in the Pomona are subleases, so you will probably have to consider a longer term lease. 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 1,980 sqft. Most properties in this market are close to 2 stories. Most buildings in this market were built in 1983 and are Class B.