The typical asking rate per listing is in the $10's per square foot per year. The Glendora region is going through a decrease in rates. In the last 3 months, the median rate decreased $10 per sqft per year. That's a 39% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Glendora submarket has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 4 listings have been posted online, which means new listings most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. 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 1,460 sqft. Most buildings in this region are close to 2 floors. Most buildings in this area were built in 1985 and are Class B.