Quoted from jeffsarcade:
I have an old 1976 Williams Space Mission that looks to be in pretty good shape near me going for about $900. Is that anywhere close to the expected value? I wouldn't mind adding an old EM machine to my basement and I do think this one is pretty cool.
They made a lot of them for a reason. Very fun game. Great art too. Steve Kordek's 2nd fav out of 100+ games.