On average, listings lease in the $10's per square foot per year. The Martinsburg region is going through a a rise in rates. In the last 3 months, the median rate increased $20 per sqft per year.
In the last 90 days, 3 listings have been listed, which means new listings might be going fast. You'll want to be prepared to make an offer immediately. 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 properties in this market are close to 2 floors. Most buildings in this area were built in 1989 and are Class C.