On average, listings lease in the $30's per square foot per year. The Downtown Rialto region is going through a a rise in rates. In the last 3 months, the median rate increased $32 per sqft per year.
Compared to the rest of the Metropolitan Los Angeles market, the Downtown Rialto submarket has lower rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 2 listings have been made available, which means spaces are probably leasing quickly. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
Even though the median size is 3,060 sqft, there are still 0 new availabilities below 2,000 sqft. Most buildings in this area were built in 1950 and are Class B.
Not much of the real estate is used for commercial space, so it might be hard to find office space. Construction is the dominant industry in this market. Most of the occupants of Downtown Rialto work from home. Commuting more than an hour and a half a day is the norm for those who opt to reside in this part of town.