Sixshot skyrocketed like crazy after ROTF. I know many G1 prices inflated after the movie, but sixshot was literally going for double the $. I remember bc I was hunting one down myself. I think it's currently holding steady at about $80-100US loose complete despite being reissued as well as darkov from tfw2005 producing heaps of custom rifles for sixxy. Maybe $150-$200 for a MIB complete one?
Those prices are based loosely on my experiences of hunting in recent months though