Most listings are in the $10's per square foot per year. The Clifton submarket is experiencing a a boost in rates. In the last 3 months, the median rate increased $16 per sqft per year.
In the last 90 days, 5 listings have come on the market, which means listings are probably leasing quickly. You'll want to be prepared to make an offer immediately. About 60% of the available space in the Clifton 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 2,480 sqft. Most properties in this area are close to 2 floors. Most buildings in this market were built in 1970 and are Class B.