Most listings are in the $0's per square foot per year. The Rialto submarket is going through a decrease in rates. In the last 3 months, the median rate decreased $32 per sqft per year. That's a 100% decline in rent.
In the last 90 days, 2 listings have been listed, which means spaces most likley are going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around sqft. Most properties in this region are around 1 stories. Most buildings in this area were built in 1993 and are Class A.