I think you are correct. Nails were in very short supply. They were used over and over.
I don’t think it’s necessarily that. I’ve read that crucifixion nails were considered lucky and/or curative, so they were sought after. Also, most of the comments are correct. There was a wide variety of crucifixion methods. Sometimes just rope, sometimes nails. The referenced Israeli find pretty much locks down that nails were sometimes used, since the heel bone was found, still nailed to wood.