The typical asking rate per listing is in the $10's per square foot per year. The Harrisburg submarket is going through a decline in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 7% decline in rent.
In the last 90 days, 18 listings have been listed, which means listings might be going fast. You'll want to be prepared to make an offer immediately. About 11% of the office spaces in the Harrisburg are subleases, so you might be able to sign a shorter term by taking over a previous lease. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,300 sqft. Most buildings in this area are around 3 stories. Most buildings in this market were built in 1936 and are Class B.