Most listings are in the $20's per square foot per year. The Smithtown region is seeing a a rise in rates. In the last 3 months, the median rate went up $4 per sqft per year. That's a 16% rise in rent.
In the last 90 days, 4 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 150% of the office spaces in the Smithtown 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 850 sqft. Most buildings in this region are close to 2 stories. Most buildings in this area were built in 1987 and are Class B.