Most listings are in the $30's per square foot per year. The Clayton region is going through a decline in rates. In the last 3 months, the median rate decreased $2 per sqft per year. That's a 5% decline in rent.
In the last 90 days, 34 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. About 3% of the available space in the Clayton are subleases, so you will probably have to focus your search on direct office leases. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
Even though the median size is 4,010 sqft, there are still 0 listings below 2,000 sqft. Most properties in this area are approximately 14 floors. Most buildings in this area were built in 1968 and are Class A.