The typical asking rate per listing is in the $30's per square foot per year. The River West submarket is going through a a boost in rates. In the last 3 months, the median rate rose $33 per sqft per year.
In the last 90 days, 7 listings have been posted online, which means leases most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 100% of the available space in the River West are subleases, so you might be able to find a shorter term or below market rent. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
Even though the median size is 2,780 sqft, there are still 0 new listings below 2,000 sqft. Most properties in this market are around 2 floors. Most buildings in this region were built in 1993 and are Class B.
Not much of the real estate is used for commercial space, so it might be hard to find office space. Utilities is the dominant industry in this market. Most of the occupants of River West work from home. Commuting close to 30 minutes a day is the norm for those who opt to reside in this part of town.