Most listings are in the $20's per square foot per year. The Dallas County region is seeing a a boost in rates. In the last 3 months, the median rate increased $24 per sqft per year.
In the last 90 days, 2432 listings have been made available, so you'll want to check back regularly for new listings. About 70% of the available leases in the Dallas County are subleases, so you might be able to sign a shorter term by taking over a previous 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 1,550 sqft. Most properties in this area are close to 3 stories. Most buildings in this area were built in 1983 and are Class B.