Most listings are in the $20's per square foot per year. The Holly Springs submarket is going through a an increase in rates. In the last 3 months, the median rate rose $3 per sqft per year. That's a 11% rise in rent.
Compared to the rest of the The Triangle market, the Holly Springs submarket has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 4 listings have been listed, which means leases most likley are going fast. 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 1,130 sqft. Most buildings in this region were built in 2007 and are Class B.