Most listings are in the $20's per square foot per year. The Dallas County submarket is seeing a a rise in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 5% increase in rent.
In the last 90 days, 1813 listings have come on the market, so you'll want to check back regularly for new listings. About 2% of the listings in the Dallas County are subleases, so you will probably have to focus your search on direct office leases. 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 1,870 sqft. Most properties in this region are close to 3 floors. Most buildings in this area were built in 1983 and are Class B.