Most listings are in the $30's per square foot per year. The Boulder region is going through a a rise in rates. In the last 3 months, the median rate went up $5 per sqft per year. That's a 19% increase in rent.
In the last 90 days, 239 listings have been listed, so you'll want to check back regularly for new listings. About 29% of the available leases in the Boulder 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.
Even though the median size is 3,050 sqft, there are still 0 leases below 2,000 sqft. Most properties in this area are close to 2 stories. Most buildings in this region were built in 1983 and are Class A.