Most listings are in the $10's per square foot per year. The Richboro submarket is going through a a boost in rates. In the last 3 months, the median rate increased $18 per sqft per year.
In the last 90 days, 1 listings have been listed, which means listings most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. 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 1,030 sqft. Most properties in this market are around 2 stories. Most buildings in this area were built in 2002 and are Class B.