The typical asking rate per listing is in the $30's per square foot per year. The Gaithersburg region is going through a decline in rates. In the last 3 months, the median rate decreased $2 per sqft per year. That's a 7% decrease in rent.
Compared to the rest of the Washington D.C. market, the Gaithersburg submarket has lower rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 20 listings have been listed, which means listings are probably leasing quickly. You'll want to be prepared to make an offer immediately. About 10% of the available leases in the Gaithersburg are subleases, so you will probably need to consider the implications of signing a direct lease with the building. 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 2,220 sqft. Most buildings in this market are close to 2 stories. Most buildings in this market were built in 1989 and are Class B.