Rega RB3000

I have a Rega Planar 3 Turntable, and I have upgraded to the Apheta 2 Cartridge.  I am now considering upgrading the Tonearm to the RB3000.  Is this a complete waste of money due to limitations of the plinth or other aspects of my deck?   I don't really want to buy a whole new turntable right now.

I have already upgraded the sub platter with Groove Tracer's product as well as reference band to drive it.  

I have the Parasound JC Jr phono preamp and my amp is PrimaLuna Evo 400.

Thank you for your comments.  I have only been doing this a few years but love it.
If it fits, it can only be an improvement. But why not upgrade the table? You know that's what you gotta do.
I'd save until I could get one of Rega's better turntables.  I'd rather have a better plinth with the RB300 than the RB3000 with a lesser plinth.  Ask your dealer about this.
I think that for little extra you get the Planar6 which is a better proposition than putting RB3000 on a P3. Just my thought.
@ronin35 For a similar price take a look at the Audiomods arm - they are so much better than anything Rega has to offer at the same price and will fit the Rega turntable perfectly.

I have never regretted getting mine - a superb piece of extremely high quality engineering.

Mine has the one-piece harness and the micrometer VTA adjustment.

Also request the Absolute harmony RCA's - they are a perfect match

Here's my review of the ARM and the RCA's

If you have any questions just ask

Regards - Steve
Thank you for all the input.  I am leaning towards upgrading to the RP8, but  I have new speakers coming so I will wait until I listen with the new speakers before I upgrade.  With Covid isolation music has been my sanctuary.  I am, therefore, having fun with upgrades.

I have had a RP6 TT for eight years. Recently I have been upgrading my system with new components, so I have to budget. I can't afford a $3000 to $6000 turntable so I've been upgrading the RP6 with a Groove Tracer sub, Rega Reference belt and an Achromat (wow!) I have been exploring upgrading the tone arm and /or cartridge.  I happened upon a good deal for an RB3000 tonearm that I couldn't say "no" to. So I'm doing it! I have a Dynavector 10x5 mk2. I want to see how the tonearm changes the sound by using the 10x5 (at least until after April 15th!). I'm thinking of upgrading to the DV xx2. I don't have other audiophiles in my world that can even understand these words I'm using! So I would appreciate feedback, thoughts, suggestions, recommendations.  Thanks!

Seems like the Origin Live tonearms will fit with the Rega mounting plates. I’ve decided that sometime here in the near future, I’m going to replace my Thorens tonearm with the Onyx. I would opt for the Silver but with a dedicated mono cartridge, it probably won’t matter that much. Anyhow, the Onyx is about $600,00 and according to what I’ve been reading, out performs many arms twice it’s price.

So I’m assuming that I’m correct in saying that an OL tonearm would be an easy install with any Rega table and they are offer a wide range. So matching the arm model with the plinth and cartridge quality would make OL a viable option.