Most listings are in the $20's per square foot per year. The Neptune Beach submarket is going through a a boost in rates. In the last 3 months, the median rate went up $3 per sqft per year. That's a 11% rise in rent.
In the last 90 days, 5 listings have been posted online, which means office spaces 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 2,010 sqft. Most buildings in this area are approximately 1 floors. Most buildings in this market were built in 2003 and are Class Class B.