Most listings are in the $10's per square foot per year. The Big Bear Lake submarket is going through a a rise in rates. In the last 3 months, the median rate went up $19 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 discounted region.
In the last 90 days, 1 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 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 2,490 sqft. Most buildings in this region were built in 2007 and are Class C.