Most listings are in the $20's per square foot per year. The Dallas County submarket is seeing a decrease in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 11% decrease in rent.
In the last 90 days, 2190 listings have been made available, so you'll want to check back regularly for new listings. About 2% of the office spaces in the Dallas County 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,230 sqft. Most buildings in this region are around 3 stories. Most buildings in this market were built in 1983 and are Class B.