How much can I sell a 1978 Littleton Micromatic Microwave for?

Well, I recently came into possession of a 1976 - 1978 micromatic microwave. It's in amazing condition and still works! It seems to be really old, and I have no use for it but I seem to find lots of vintage posters on it, so I just wanted to see if it actually had any monetary value. Any info would be nice. Thanks!