You both could take up airbrushing or cake decorating as a hobby. The compressor is powerful enough to do it so why buy an art compressor if you can do it with this used one.
Seriously, there are places that will take donations of still working, in good condition, medical equipment. It will depend on what state you are in or if you care where it goes. Red Cross is one. But it just depends on if there is a need for the equipment when you want to go donate it. Some local medical mission groups also will.