On average, listings lease in the $20's per square foot per year. The Lilburn submarket is going through a a rise in rates. In the last 3 months, the median rate increased $22 per sqft per year.
Compared to the rest of the Metro Atlanta market, the Lilburn region has smaller rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 3 listings have been posted online, which means office spaces most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 233% of the available space in the Lilburn are subleases, so you might be able to find a shorter term or below market rent. 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 720 sqft. Most buildings in this market are around 1 floors. Most buildings in this area were built in 1986 and are Class C.