Compared to the rest of the Metropolitan Los Angeles market, the Yucaipa region has lower rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 8 listings have been listed, which means new listings 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 on the market, 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 market were built in 2008 and are Class B.