Cartridge upgrade

If you would like to upgrade whithout spending too much then MM or MI path is the best, in $400-1500 you can buy some exceptional cartridges, mostly vintage ones (from the 70s/80s), but can be found NOS (unused). You already have an MC from respected manufacturer, maybe you want to try some killer MM or MI ? If your top is $1500 believe me it’s enough for the very best ones!

Have you heard about Miyajima cartridges ? Models like Shilabe and Kansui ? They are not in your price range, but if you're looking for some organic sound then try them. 

I'm sure Fidelity-Research MC cartridges like Fr-7f or PMC-3 is what you have to check for the same reason if you have the right tonearm for them. 

Clearaudio cartridges made by Audio-Technica (with AT generators) if you don't know. The vintage AT-ML180 OFC is unbeatable, but very rare!  Victor X-1II is another vintage MM adored by many on audiogon, simply seach for feedbacks from many users. 

 

Well, Denon 103 is also widely popular cartridge, but it's absolutely awful.
Popularity means nothing as much as the professional reviews. 

I've noticed that some people who likes modern cartridges never ever tried some of the the best vintage cartridges today in camparison to those overpriced modern ones. 

FR-7fz (which would also cost you around $1500 in ’previously cherished’ condition).

Once in 5 years only if you’re lucky, more realistic price nowadays is something like $2500 and it will be sold pretty quick as they are mega rare. I’ve noticed that even FR-7f is often available for sale re-tipped, but sellers didn’t give a word about it in the listings (i can see too much glue around the diamond). So the buyer must be an expert to recognize fake diamond.

Interesting info about Phasemation, they are popular only among the Japanese audiophiles. Have you tried PP-1000 ?