The typical asking rate per listing is in the $20's per square foot per year. The Beavercreek region is experiencing a a boost in rates. In the last 3 months, the median rate went up $2 per sqft per year. That's a 10% increase in rent.
In the last 90 days, 14 listings have come on the market, which means leases most likley are 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 2,000 sqft. Most properties in this market are around 2 floors. Most buildings in this area were built in 1989 and are Class B.