The typical asking rate per listing is in the $20's per square foot per year. The Manhattan region is going through a an increase in rates. In the last 3 months, the median rate increased $5 per sqft per year. That's a 25% increase in rent.
In the last 90 days, 10 listings have been listed, which means spaces are probably going fast. You'll want to be prepared to make an offer immediately. 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 2,000 sqft. Most properties in this market are around 1 stories. Most buildings in this market were built in 1984 and are Class A.