There is one thing very unique about that dishwasher. That model has, or at least some of them have, a metal impeller and it was the only year WH used a metal impeller. The leading edges of it did not become dull or chipped like the Bakelite ones. If it is intact and not destroyed by a knife that fell on it, it gives very good washing action. Robert discovered this with his machine like this one.
It is not, however, worth that price to most collectors. This is someone who thinks that anything old is made of gold and it ain't.