On average, listings lease in the $20's per square foot per year. The West Chester region is going through a decline in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 10% decrease in rent.
In the last 90 days, 7 listings have come on the market, which means new availabilities might be going fast. You'll want to be prepared to make an offer immediately. About 200% of the listings in the West Chester 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 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 1,000 sqft. Most buildings in this area are around 3 stories. Most buildings in this region were built in 1930 and are Class A.