The typical asking rate per listing is in the $10's per square foot per year. The Tyler submarket is going through a an increase in rates. In the last 3 months, the median rate increased $18 per sqft per year.
In the last 90 days, 12 listings have been posted online, which means leases most likley are going fast. You'll want to be prepared to make an offer immediately. About 92% of the available space in the Tyler are subleases, so you might be able to snag a great spot on a short term. 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 2,300 sqft. Most buildings in this market are approximately 2 stories. Most buildings in this region were built in 1980 and are Class B.