On average, listings lease in the $10's per square foot per year. The Deerfield submarket is going through a decline in rates. In the last 3 months, the median rate fell $4 per sqft per year. That's a 18% decrease in rent.
Compared to the rest of the Chicagoland market, the Deerfield region has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 13 listings have been made available, which means leases most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 8% of the available space in the Deerfield 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.
Even though the median size is 3,520 sqft, there are still 0 new availabilities below 2,000 sqft. Most properties in this market are around 4 floors. Most buildings in this market were built in 1986 and are Class A.