The typical asking rate per listing is in the $30's per square foot per year. The Lake Forest region is experiencing a an increase in rates. In the last 3 months, the median rate rose $3 per sqft per year. That's a 11% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Lake Forest submarket has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 29 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. About 3% of the listings in the Lake Forest are subleases, so you will probably have to focus your search on direct office leases. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
Even though the median size is 6,010 sqft, there are still 0 office spaces below 2,000 sqft. Most properties in this market are around 2 floors. Most buildings in this area were built in 1999 and are Class B.