What is a good turntable preamp under $500?

Those Regas are not great values in my opinion.  The Pro-Ject Debut EVO is the pick of the litter for $600.00.  Your CA preamp will serve adequately...it's probably a $200.00 item.  The PF-20 is a toy, but better than any Garrard idler drive mass market 'table. The Rainier on the EVO will be better than the Grado, too.  If you want a new preamp, nothing will beat the Mani 2 for the $$$.  You seem to be budget constrained, so hitting the peak value quotient is essential.

Replace the TT and keep the phono preamp for now.

Take a look @ Grislybutter's new thread for a TT pretty much in your price range.

DeKay

So much bad advice it truly boggles the mind. Unless you upgrade from the Pioneer Elite you will spend money spinning your wheels. What Grado MM, I assume, (you wrote "nm") cartridge and stylus are you using? It has to start there. The Yamaha tt may not be awful but the cartridge determines everything, even if you keep the Pioneer Elite for the time.

Yes, I meant to type MM. The Grado is a low level cartridge, I think it is called Prestige Black. Again, I know this equipment is considered lo-fi, but my original intention was just to see if I could get my turntable up and running. I have a Classe SSP in my main rig, but it only has one analog input, which I am using for my Lumin streamer. Hence the reason I am using the Pioneer receiver in a second configuration for the turntable. I have no intention of trying to get to the level of my digital system, but was hoping to find out the first step to improve it ( turntable, cartridge, or preamp).

The Schiit Mani2 phono preamp- Fremer gave it a very positive review:

https://www.analogplanet.com/content/schiits-mani-2-mmmc-phono-preamp-goes-head-budget-phono-preamp-class-0

Schiit makes high value components consistently performing above their price point.   At $150, this looks like a bargain.

Schiit’s website still shows the Mani and not the Mani2, but per Schiit after ordering:  ”To answer your questions, yes you will be receiving the Mani2 since Mani V1 is no longer available since it's been discontinued. ”