Sony PS-X9

True that. I’ve only ever seen it in photos. JP Jones owns one I think. Perhaps he has an informed opinion.

JP does have one that came with an SME arm mounting board,
if I recall correctly replacing it with another original board
was proving very difficult. 

If you're referring to replacement of the tonearm mount, that's neither here nor there, as regards the "goodness" of a PS-X9.  I do think JP likes his very much, however, at least on the technical level.  Personally, among the classic Japanese direct-drives that I don't own, I most lust for an Exclusive P3.  On the other hand, I am very very happy with what I do have.

Is this the table?

https://www.ebay.com/itm/SONY-PS-X9-TURNTABLE-fully-restored-with-remote-and-Phono-output-stage-rest...

Unquestionably, an engineering masterpiece. Value  naturally, is in the wallet of the buyer.

I would test the waters however, and see where this sellers "selling price" is.

If I were into something like this, I would stress to the seller you have cash READY to wire at a better negotiable price.

$13K buys much more choice in the latest gear WITH a dealer to support your purchase.

Hi,$13k sounds high, Ive seen them sell for around £5k gbp over the years I've been looking..