Cartridges

Have heard stellar reviews

Axia to Epoch 3 is indeed a big jump, price wise. You would have to determine if your table/arm/phono could also support the improvements.

Even looking at $6k carts opens doors to a large uptick in performance imho

What table and arm are you going to put the $12000.00 Grado on?  What are the other components in your system?

Best cartridge/arm/table/phono preamp.

or

a new car

I am not totally sold on the Epoch yet. I would like to see what Grado is using for a stylus. I also will not spend more than $100 for a record and I have very few 100 dollar records. 
 

In order to get the performance out of a great recording you need a great record playing system. I put the record and the system in two entirely separate compartments. As was said above you need both.

The cartridge depends on the tone arm and the phono stage.