Agree with most that used cartridges are too risky to buy. Many dealers will give you 20% discount so just buy new.
Sure, but when I was younger 20 - 25% off a Koetsu still didn’t make it affordable to me. I bought my first Koetsu used, and it gave me a big taste of the high end, which I continue to enjoy today. Bought my next Koetsu used too, and also loved it. At some times the used price of a high end cartridge with "~ 300 hours" has been low enough that even when adding the cost of a factory rebuild, it still comes out to a new cartridge at ~ 20% off list. And the used Koetsu I bought from here definitely didn’t need to be rebuilt for a while. I’ve since bought new ones & had factory rebuilds - the used ones definitely sounded like they should.
As others have stated, it’s fine that so many in this market are reticent to buy a used cartridge - it makes better deals for the rest of us. On the other hand, it sucks when selling, but I don’t do that much 😅