The typical asking rate per listing is in the $30's per square foot per year. The Mount Pleasant submarket is going through a a boost in rates. In the last 3 months, the median rate increased $3 per sqft per year. That's a 9% increase in rent.
In the last 90 days, 35 listings have come on the market, which means office spaces most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 11% of the listings in the Mount Pleasant 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,450 sqft. Most properties in this region are around 2 stories. Most buildings in this region were built in 2002 and are Class A.