I had a metal building constructed with gable ends only- no front or back walls.
I then went to Lowes and ordered matching sheet metal panels, purchased 4x4 posts, and ordered roll up doors to my specifications (one with an opener).
I set the posts, mounted the panels, and hung the doors myself.
Oh, I also installed a man door that I found at a scrap yard.
It would have been $7,500 more to get those options from the builder.
It cost me about $1500 and my own labor, at my own pace.