Most listings are in the $10's per square foot per year. The Warren County region is going through a an increase in rates. In the last 3 months, the median rate rose $15 per sqft per year. That's a Inf% rise in rent.
In the last 90 days, 8 listings have come on the market, which means new availabilities most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 13% of the available leases in the Warren County are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 900 sqft. Most properties in this market are close to 2 stories. Most buildings in this region were built in 1960 and are Class B.