On average, listings lease in the $20's per square foot per year. The Tomball region is going through a a boost in rates. In the last 3 months, the median rate increased $24 per sqft per year. That's a Inf% increase in rent.
Compared to the rest of the Houston Metro market, the Tomball submarket has lower rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 7 listings have been posted online, which means new listings most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
Even though the median size is 3,000 sqft, there are still 0 leases below 2,000 sqft. Most buildings in this region are approximately 1 floors. Most buildings in this region were built in 1983 and are Class B.