1 The average office space in the United States is around $39 per square foot according to CushWake.com. 2  An office building in Indianapolis will run around $25 per square foot. 3  An office building in downtown New York City will run around $65 per square foot. There are going to be many factors that need to be factored in. 2  The location of the building, the amenities, the age of the building, the foot traffic and more will greatly influence the price. 3  The average office space in the United States is around $39 per square foot according to CushWake.com.