Phono preamp worth it with MM cartridges?

If you don't want to change tables, upgrade the arm of the P3 to an RB880. I did it when I had a P5 and was blown away (I subsequently but the bullet and got the P8 which includes it).  If you add a PSU if you don't have one, the table will be very good. Depending on the dealer trade value of your P3, it might be worth it to jump to the P8 which of course includes the PSU. Rega is known for their arms. Take advantage of them.

Cartridge upgrade would help too. The need for a phono stage is more apparent with MC cartridges, although they can also help with MMs. Since most MMs today are junk, I would recommend a reasonable MC and a Sutherland phono stage, the highest level one you can afford. That's all they do.

The very first post suggested SimAudio Moon phono stages ,
My first external was a 110LP replacing the wall wort with a linear power supply  and can say that the improvement was very rewarding compared to the built in found in the pre-amp that   I was using at the time, 
along with Grado Wood cartridges on a Rega 300rb arm .

A few years ago I upgraded and went with tubes and purchased a
Tavish Design Adagio , this unit is under your $2,000 limit .
I'm now using a Soundsmith Carmen mkII on the same Rega 300rb arm .

Tubes are great but they can be expensive ,
the Moon 110LP is a great unit for it's price but has limited settings .
Either way using an external phono pre-amp will benefit any MM cartridge that you'll use .

Sound, flexibility, price: iFi.

@samzx12

jjss49 you bring up a good point. I did try a few different settings. What did you decide on worked best in your setup?

iirc i settled on 22k ohms for the at ml150

Except for speakers, I have almost the exact same gear. First off, I think the Exact is excellent, and I’m on my second one. I run a Parks Audio Budgie as my phono amp, and couldn’t be happier with the sound. They don’t come up for sale that often, but with some reasonably priced vintage tubes that I got off of EBay, it sounds really nice. Just another option. And I’d love to hear the A4’s with my gear.