Most listings are in the $10's per square foot per year. The Oshkosh submarket is going through a a rise in rates. In the last 3 months, the median rate rose $0 per sqft per year. That's a 2% rise in rent.
In the last 90 days, 4 listings have been posted online, which means office spaces most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. 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 2,100 sqft. Most buildings in this area are approximately 2 stories. Most buildings in this area were built in 0 and are Class B.