Jun 30, 2020 · For square tube posts, you can expect to pay between $13 and $20 per foot. Posts which are of the large steel breakaway variety are more expensive and average between $40 and $50 per foot. A cantilevered sign will be somewhere between $50,000 and $60,000 for each structure, and a sign bridge will be between $80,000 and $100,000 for each structure.