Most listings are in the $0's per square foot per year. The Roslyn region is going through a decline in rates. In the last 3 months, the median rate fell $60 per sqft per year. That's a 100% decrease in rent.
In the last 90 days, 0 listings have been listed, which means listings most likley are going fast. You'll want to be prepared to make an offer immediately. About NaN% of the available leases in the Roslyn are subleases, so you will probably have to consider a longer term lease. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around sqft. Most buildings in this area were built in 1900 and are Class C.