Compared to the rest of the Metropolitan Los Angeles market, the Yucaipa submarket has smaller rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 8 listings have come on the market, which means office 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 780 sqft. Most buildings in this area were built in 2008 and are Class B.