The typical asking rate per listing is in the $20's per square foot per year. The Dallas County submarket is experiencing a a rise in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 3% increase in rent.
In the last 90 days, 2432 listings have been listed, so you'll want to check back regularly for new listings. About 3% of the available leases in the Dallas County are subleases, so you will probably need to sign a longer term lease with the landlord directly. 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 1,210 sqft. Most properties in this area are close to 3 stories. Most buildings in this region were built in 1983 and are Class B.