Most listings are in the $10's per square foot per year. The Smith County region is seeing a a rise in rates. In the last 3 months, the median rate rose $2 per sqft per year. That's a 11% increase in rent.
In the last 90 days, 13 listings have been listed, which means leases most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 46% of the available leases in the Smith 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,100 sqft. Most properties in this region are around 1 floors. Most buildings in this market were built in 1980 and are Class B.