On average, listings lease in the $10's per square foot per year. The Iowa City submarket is experiencing a an increase in rates. In the last 3 months, the median rate went up $2 per sqft per year. That's a 10% rise in rent.
In the last 90 days, 24 listings have been made available, which means new availabilities are probably going fast. You'll want to be prepared to make an offer immediately. About 33% of the available space in the Iowa City are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 1,190 sqft. Most buildings in this market are around 2 stories. Most buildings in this market were built in 1989 and are Class A.