Most listings are in the $10's per square foot per year. The Big Bear Lake region is going through a an increase in rates. In the last 3 months, the median rate went up $17 per sqft per year.
Compared to the rest of the Metropolitan Los Angeles market, the Big Bear Lake submarket has less expensive rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 1 listings have been listed, which means leases are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. 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 860 sqft. Most buildings in this region were built in 2007 and are Class C.