Vortex Sound Research

This isn't a sales post, so it didn't seem appropriate for /r/synths4sale. I apologize in advance if this is the wrong venue for this type of question!

Basically, I'm thinking about selling my Korg workstation keyboard and it's missing a knob (6mm d-shaft, I think), do you think it's worth it to seek out and buy a set (4 knobs) of aftermarket replacement knobs before trying to sell it or is it better to just list it "as is" with the missing knob?

Right now the missing knob is kind of a black eye on an instrument that is otherwise in pretty good condition, in my opinion.