The typical asking rate per listing is in the $10's per square foot per year. The Fort Pierce region is going through a a rise in rates. In the last 3 months, the median rate increased $2 per sqft per year. That's a 11% rise in rent.
In the last 90 days, 97 listings have come on the market, so you'll want to check back regularly for new listings. About 3% of the listings in the Fort Pierce are subleases, so you will probably have to focus your search on direct office leases. 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 1,250 sqft. Most buildings in this market are around 1 stories. Most buildings in this area were built in 1983 and are Class B.