On average, listings lease in the $30's per square foot per year. The Manhattan submarket is seeing a a rise in rates. In the last 3 months, the median rate rose $38 per sqft per year.
In the last 90 days, 10 listings have been listed, which means leases most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 50% of the available space in the Manhattan 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 1,270 sqft. Most buildings in this market are around 1 floors. Most buildings in this area were built in 1984 and are Class A.