The typical asking rate per listing is in the $20's per square foot per year. The Bel Air region is going through a a boost in rates. In the last 3 months, the median rate rose $21 per sqft per year.
Compared to the rest of the Greater Baltimore market, the Bel Air region has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 3 listings have been posted online, which means leases 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.
Even though the median size is 6,090 sqft, there are still 0 office spaces below 2,000 sqft. Most properties in this market are around 2 stories. Most buildings in this market were built in 1998 and are Class B.