The typical asking rate per listing is in the $10's per square foot per year. The Crystal Lake region is experiencing a decline in rates. In the last 3 months, the median rate decreased $5 per sqft per year. That's a 22% decline in rent.
Compared to the rest of the Chicagoland market, the Crystal Lake region has smaller rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 31 listings have been posted online, which means listings most likley are going fast. 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 1,640 sqft. Most properties in this market are close to 1 stories. Most buildings in this area were built in 1995 and are Class A.