I guess you are talking about MC carts, as replacement stylus in MM carts are a non-issue, IMHO. I had my SoundSmith Zephyr MIMC* rebuilt by SoundSmith after a mishap, and I have zero issues with that.
With antique carts, I would rather consider them display items.
Re slightly used, Audible Elegance just posted a video on used carts and strongly advises against them. Particularly the degrading suspension is an issue, and not perfectly aligned, partially worn stylus can damage records.