I avoided buying used cartridges, until I decided to risk it. This seller is one I trust and would buy again from:
https://reverb.com/item/95620911-audio-technica-vm760slc-vm-type-stereo-cartridge-w-hs-4-headshell-from-japan
It has their best stylus, Special Line Contact, which also has the longest life due to it’s largest amount of contact area (which requires excellent alignment).
It’s cantilever is aluminum, I don’t know why they didn’t use boron, perhaps to offer the best stylus, and keep the price down a bit. We have all had excellent sounding cartridges with aluminum.
As far as Imaging, it has 30db separation, and channel balance of 1.0 db. To get tighter 0.5db channel balance you will need to spend a good bit more.
Here is the newer x version, boron cantilever, and body threads for easier mount.
https://www.audio-technica.com/en-eu/cartridges/type/moving-magnet/at-vm760xsl
btw, these are MM, with the advantage of user replacable stylus.
https://www.audio-technica.com/en-eu/vmx-series-cartridge
If you ever see a discontinued model, even one with a worn tip, broken cantilever (I've done that twice) a new stylus, even an upgraded one may be possible, or have a re-tipper like VAS re-build it.
https://www.audio-technica.com/en-eu/support/which-stylus-can-i-use-to-replace-my-discontinued-model