On average, listings lease in the $30's per square foot per year. The Ontario region is seeing a an increase in rates. In the last 3 months, the median rate rose $31 per sqft per year.
Compared to the rest of the Metropolitan Los Angeles market, the Ontario submarket has lower rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 71 listings have been listed, so you'll want to check back regularly for new listings. About 92% of the office spaces in the Ontario are subleases, so you might be able to snag a great spot on a short term. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
Even though the median size is 3,290 sqft, there are still 0 listings below 2,000 sqft. Most properties in this area are around 2 floors. Most buildings in this region were built in 1999 and are Class A.