On average, listings lease in the $30's per square foot per year. The Clayton submarket is going through a a boost in rates. In the last 3 months, the median rate increased $1 per sqft per year. That's a 4% rise in rent.
In the last 90 days, 35 listings have been listed, which means new availabilities most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 34% of the office spaces in the Clayton are subleases, so you might be able to find a shorter term or below market rent. 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 1,750 sqft. Most properties in this market are close to 12 stories. Most buildings in this market were built in 1968 and are Class A.