On average, listings lease in the $30's per square foot per year. The Smithtown submarket is experiencing a a rise in rates. In the last 3 months, the median rate increased $16 per sqft per year. That's a 67% increase in rent.
In the last 90 days, 3 listings have been listed, which means listings most likley are going fast. You'll want to be prepared to make an offer immediately. 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 500 sqft. Most buildings in this area are around 2 floors. Most buildings in this region were built in 1987 and are Class B.