A few years ago, I "sold" usage rights for 5 files for our local hospital remodeling/addition to the contractor's agent doing the work. I charged 150.00 per file. I requested my copyright and name remain on each image. Found a general contract on the internet and used that. It was for a "one time" use only. The images were framed and hung in various places in the hospital. They wanted "local" photographers images of the area.