How funny! I mean how rare is it to find an Apple II in the garbage? No, I mean, aren't they commonly found in the... No, that's not it either.
It is a good solid 8-bit computer; very expandable and used is academic, work place, and in recreational settings. No well equipped lab circa 1980 would be without one and with VisiCalc it helped to change a paradigm.
But Dude, did you Google anything but porn? Rare? Worth 5 Grand?