The typical asking rate per listing is in the $10's per square foot per year. The Sebastian region is going through a a boost in rates. In the last 3 months, the median rate increased $16 per sqft per year. That's a Inf% rise in rent.
In the last 90 days, 2 listings have come on the market, which means leases might be 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 2,000 sqft. Most buildings in this market are around 2 stories. Most buildings in this area were built in 1973 and are Class C.