On average, listings lease in the $20's per square foot per year. The Colleyville submarket is going through a decrease in rates. In the last 3 months, the median rate fell $4 per sqft per year. That's a 14% decline in rent.
Compared to the rest of the DFW Metroplex market, the Colleyville region has less expensive rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 13 listings have been posted online, which means spaces most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. 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 1,480 sqft. Most buildings in this area are around 1 floors. Most buildings in this region were built in 2006 and are Class B.