At what price point do I run into diminishing returns on an MC Cartridge?

Norman, pay attention to atmasphere. He is very right. Learn to set up your tonearm and cartridge correctly. You will do it better than anyone else just because it is your turntable. Do not believe any of the scales on the tonearm. You need a test record, an accurate stylus force gauge, a level, a few tools and patience. It is not rocket science. 

Dear @daveyf  : I owned Linn cartridges , the last one was the Akiv.

As Lyra Linn cartridges are manufactured by Scan-Tech not by Lyra.

I never had the opportunity to listen the Kandid but something that worried me about the Linn characteristics design is that ceramic boron cantilever due that ceramic is way resonant in that place.

Lyra Clavis D'Capo came with a ceralloy cantilever, I owned and when I change that cantilever for a boron one the differences for the better was nigth and day.
Lyra knows that and I don't think that could recomend to any one a ceramic/boron cantilever type.

The Akiva is very good performer and I can assume that the Kandid too.

@normantaylor , as the quality level performance increase in a cartridge the improvements in new cartridge designs goes in lower and lower increments but the prices goes higher and higher because when the quality levels is so high any tiny increment in the quality performance levels is an achievement not easy to touch. Needs a lot of research and tests/voicing evaluations and that means time, knowledge and skills to do it to " stay there " and this means too a lot more money for a tiny quality increment..

But all those does not matters if you don't have the room/system quality level performance that can honor that cartridge so high qualityperformance. Of course that that room/system needs a really high resolution levels with extremely low overall distortions and you need very experienced ears not only in audio but in live MUSIC and how it sounds at near field seated position.

Now, you started this thread and other two threads in other forums where in the other forums you were asking for amp or speaker and your budget limit is 12K and now are you looking for a cartridge on the $$$$$ price that can goes over that small budget of what you are looking for? or maybe you already left the speaker or amp for other future times. Who knows.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

I am reminded of Mikey Fremer's blind test of 8 cartridges a few years ago which you can still find on Analog Planet.  He set up sound samples for us to listen to of cartridges ranging in price from just a few hundred dollars for a few MM to over $8000 for an Ortofon Anna.  The majority of participants preferred an Audio Technica MM cartridge overall that retailed for about $750 at the time.  Later it was revealed that Mikey had inadvertently set the gain wrong or something, which kind of spoiled the outcome, but really only by a whisker.  The point is that the differences are not so great between well designed and set up cartridges as we might think, and it is possible to obtain stellar results from modest cartridges if you are meticulous about setup.  I happen to own both the $750 cartridge that won Mikey's competition and a Soundsmith Hyperion ($8000) and can tell you for a fact that there is not a great a difference between them.  By every account the Hyperion is among the top cartridges in the world.  So one answer to your question might be $750.

YES!  Set-up, set-up, set-up. Get a first class tonearm which is completely adjustable, and set it up carefully, over a few months.

I use two Trans-Fi Terminator air bearing tonearms ($1000 buys the best deal in high end). Easy to set up. Stable. Retain their adjustments.

As for the cartridge, don't forget that some wear a whole lot better than others. And some cost more for a factory retip than others. My Koetsu still looks good after 1000 hours - but when it becomes necessary, the retip cost is ruinous.

Dear @rauliruegas Scan Tech and Lyra are basically one and the same!
Scan Tech is the corp name...Lyra is the brand name. So, like I said before...the Kandid is made by Lyra...or if you prefer by Scan Tech....same folks.
Is there anything you don’t want to correct on these forums??