On average, listings lease in the $10's per square foot per year. The Green Bay submarket is going through a a rise in rates. In the last 3 months, the median rate increased $1 per sqft per year. That's a 8% rise in rent.
In the last 90 days, 39 listings have been listed, which means leases are probably leasing quickly. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,390 sqft. Most buildings in this region are approximately 2 floors. Most buildings in this market were built in 1960 and are Class B.