Most listings are in the $10's per square foot per year. The Arlington region is experiencing a decline in rates. In the last 3 months, the median rate decreased $4 per sqft per year. That's a 17% decrease in rent.
Compared to the rest of the DFW Metroplex market, the Arlington submarket has smaller rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 61 listings have been listed, so you'll want to check back regularly for new listings. About 7% of the office spaces in the Arlington are subleases, so you will probably have to consider a longer term lease. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,810 sqft. Most buildings in this market are close to 2 stories. Most buildings in this area were built in 1985 and are Class B.