The typical asking rate per listing is in the $20's per square foot per year. The Wheaton region is going through a an increase in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 2% rise in rent.
Compared to the rest of the Chicagoland market, the Wheaton submarket has more expensive rates, and you'll need to make a great offer to be in this hot region.
In the last 90 days, 126 listings have been posted online, so you'll want to check back regularly for new listings. About 42% of the listings in the Wheaton 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 360 sqft. Most properties in this area are around 2 stories. Most buildings in this area were built in 1988 and are Class B.