Most listings are in the $20's per square foot per year. The Lenexa region is going through a a rise in rates. In the last 3 months, the median rate increased $2 per sqft per year. That's a 7% rise in rent.
In the last 90 days, 29 listings have been made available, which means spaces most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 3% of the available leases in the Lenexa are subleases, so you will probably need to sign a longer term lease with the landlord directly. 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 3,000 sqft, there are still 0 leases below 2,000 sqft. Most buildings in this area are around 1 stories. Most buildings in this region were built in 1988 and are Class B.