Compared to the rest of the Metropolitan Los Angeles market, the Big Bear Lake region has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 1 listings have been posted online, which means listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. 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 2,490 sqft. Most buildings in this region were built in 2007 and are Class C.