Looking for the best moving coil cart that is around $5K used

I agree with tooblue.  Although the rewards might not come immediately, and it may require work on your part, I believe $5,000 is too much to spend on a cartridge, when your turntable seems to be a limiting factor(I have to admit to not being a fan of the one Scout[or Scoutmaster], although modified, I heard at a show.  It was not very dynamic, or emotion-inducing to me, but may have been limited due to the modifications.).

Papafrgog, I wouldn't worry so much about what others here say regarding your Linn.  First, I got to hear needledrops on PinkFish Media that, to me, showed me that a Linn Lp12 was the best of the bunch, which included an SME and the old Technics direct drive(with mods), among others.  The thing is, with music, it's not all an intellectual exercise.  In other words, you can get enjoyment from the actual music, unlike some other hobbies, where you worry if you really have the best.  Number 2:  I heard the Technics SP10 from a well-known audio company, and they also  do mods to this turntable.  It was not in the same league as a well set up Linn, at least by my standards, which includes enjoying the music, and getting off on it(maybe affecting you emotionally?).