I'm collecting bids for putting a steel structure over a parking lot in my newly acquired apartment complex, and thought the community might like to see some of the prices I've been quoted.  For a linear array of 14 spaces, including installation, I was quoted about $28k for full cantilever (posts at the very end) or about $25k for semi-cantilever (posts offset from the end by 7.5'.  Semi-cantilever is less expensive, because it doesn't need to have quite as much strength to offset the huge leverage at the very end of the structure.

This project is in Mesa, AZ