I wonder what kind of charity would take an Amiga computer? Even if he were to "donate" it somewhere, at least it stands a chance of finding a good new home. That's better than binning it at least.
I've seen Commodore, Atari, Amiga, and other old computer stuff at Goodwills, Missions, and various other charity thrift shops within the past several years. A couple of years back a local place had an Apple IIgs.