@unreceivedogma,
'I found the Shure V15 type III, IV, V and MR on eBay.
ONE of them is supposed to be the one, the others, also-rans.'
I'm afraid I don't know enough about them apart from their no nonsense sturdy all-round reputation. Domestic products can have all kinds of conflicting reputations but established products used professionally in broadcasting can be regarded as far more dependable.
When buying used it's probably just as important to have a look at the seller in as much detail as the product or the price.
I have never bought a used cartridge having always preferred to start with a new stylus, so I'd be pretty nervous too.
There are definitely some dubious sellers/dealers out there who tend to leave a lot of information out of their ads.
Perhaps they just forget.
On the other hand there are some exemplary sellers out there who will readily disclose the most minor issue or blemish.
A perennial problem for not only an audiophile is the conflict between the heart and the head. Right now I'm asking myself if I really need another CD player as a backup, just in case.
It's really irrational, and probably no more than a sign of a lack of focus, but there's something really warm and enticing about looking for an audio product.