I'm selling a barely used Nuova Simonelli Mythos Clima Pro grinder (the one with temperature stability features). I acquired it for a pop-up as a second grinder, but ended up only needing one. Very clean, less than 40 lb of coffee have been run through this grinder, and it works perfectly.
If you're a home user, this is pretty much the industry standard grinder to go for with super low grounds retention.
If you're a shop owner, this grinder can save you up to $1000 each year in wasted coffee. Super low retention means less purging in between grind adjustments, temperature stability means your grind stays consistent, and a precise timer means less coffee wasted when dosing.