Experiences buying used cartridges

I have bought a number with no problem. Do a search. This is not a new topic.

I've bought over 40 used or NOS cartridges and styli with only a handful of disappointments.
Of course some of those cartridges did not impress or appeal to me and I on-sold them at virtually no loss.
I find that many classic MMs of the '70s and 80s sound more cohesive and emotional than modern designs and even some noted LOMCs of the same era can compete with their current brethren.
I've had many more disappointments with 'new'' cartridges and it would take some serious word-of-mouth for me to outlay again for a 'new' current model.
And then there's the cost differential 👅

I've bought and sold pre-owned cartridges on Audiogon many times. Never had a bad experience. Of course, I check member feedback pretty carefully.

My current cartridge is a pre-owned Lyra Kleos, ... which I bought lightly used a while ago. Still works like a charm.

Buying preowned cartridges is a higher risk proposition, but if you buy from a reputable member with a good reputation, it may be a risk worth taking considering the potential savings.

Very bad idea!!

Here's a question for those who are considering a used cartridge...how do you really know how many hours on that piece? Therefore, how much wear has the diamond incurred...because just a few playings of a worn diamond and your LP's are toast.