The typical asking rate per listing is in the $20's per square foot per year. The Baytown region is going through a an increase in rates. In the last 3 months, the median rate went up $22 per sqft per year.
Compared to the rest of the Houston Metro market, the Baytown submarket has less expensive rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 7 listings have been posted online, which means spaces 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 on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,700 sqft. Most buildings in this area are around 1 floors. Most buildings in this area were built in 1985 and are Class B.