Most listings are in the $20's per square foot per year. The Madison submarket is going through a decrease in rates. In the last 3 months, the median rate decreased $2 per sqft per year. That's a 7% decrease in rent.
In the last 90 days, 95 listings have been listed, so you'll want to check back regularly for new listings. About 1% of the listings in the Madison are subleases, so you will probably need to consider the implications of signing a direct lease with the building. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,840 sqft. Most buildings in this region are close to 2 stories. Most buildings in this market were built in 1987 and are Class B.