Most listings are in the $10's per square foot per year. The Orange Park region is going through a decline in rates. In the last 3 months, the median rate decreased $3 per sqft per year. That's a 14% decline in rent.
In the last 90 days, 8 listings have been made available, which means listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. 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 1,000 sqft. Most properties in this region are around 1 floors. Most buildings in this area were built in 1988 and are Class B.