Possible reasons for their asking for offers. 1), they don't care what it take just get rid of it. 2), they really are clueless as to its value. 3), there is something wrong with the machine and don't want to risk selling a 'lemon' and any lawsuit afterwards.
I'd take the chance to see if it powers up and moves around properly. But trying to move that behemoth with limited resources is the bigger challenge.