Most listings are in the $10's per square foot per year. The Sullivan County submarket is going through a decline in rates. In the last 3 months, the median rate decreased $1 per sqft per year. That's a 4% decline in rent.
In the last 90 days, 13 listings have been made available, which means new listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 85% of the available leases in the Sullivan County are subleases, so you might be able to snag a great spot on a short term. 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 860 sqft. Most properties in this area are around 2 floors. Most buildings in this region were built in 1930 and are Class Class B.