On average, listings lease in the $20's per square foot per year. The Williston submarket is seeing a an increase in rates. In the last 3 months, the median rate increased $21 per sqft per year.
In the last 90 days, 9 listings have been posted online, which means new availabilities most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 33% of the available space in the Williston are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 750 sqft. Most buildings in this area were built in 2011 and are Class A.