The typical asking rate per listing is in the $10's per square foot per year. The Yucaipa region is seeing a a rise in rates. In the last 3 months, the median rate increased $16 per sqft per year. That's a Inf% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Yucaipa submarket has less expensive rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 13 listings have been posted online, which means listings most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. 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 930 sqft. Most buildings in this area were built in 2008 and are Class B.