Most listings are in the $20's per square foot per year. The Manassas submarket is seeing a decrease in rates. In the last 3 months, the median rate decreased $2 per sqft per year. That's a 10% decline in rent.
Compared to the rest of the Washington D.C. market, the Manassas 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 listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 7% of the listings in the Manassas are subleases, so you will probably have to consider a longer term lease. 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 2,190 sqft. Most properties in this market are around 2 stories. Most buildings in this region were built in 1989 and are Class B.