On average, listings lease in the $10's per square foot per year. The Nampa region is experiencing a decrease in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 12% decline in rent.
In the last 90 days, 36 listings have been listed, which means office 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 Nampa are subleases, so you will probably have to consider a longer term lease. 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 1,690 sqft. Most buildings in this region are approximately 1 floors. Most buildings in this area were built in 2002 and are Class A.