Time to upgrade my turntable?

This Technics SL-1200GR or SL-1500C would be a nice upgrade. It might be more than your budget but you set 'em and forget 'em!
https://www.technics.com/us/products/grand-class/sl1200g-series/sl-1200gr.html
https://www.technics.com/us/products/premium-class/sl-1500c.html

Right, between GR and 1500c I would add new mk7 which is exactly $1000 with warranty, sometimes it cost even less! 

The problem with some audiogon posters is complete lack of knowledge about Technics products and other Japanese Direct Drives, most people brainwashed by belt drive propaganda.     

Ortofon can be expected to claim the cartridge is the most important element. But the best cartridge in the world will sound terrible if the turntable and arm are not well enough engineered to retain the stylus in precisely the correct orientation in the groove.  

People do not use GRAMOPHONES these days, modern turntables are very well engineered and tonearms are nice, even those cheap Rega and Project are good toys. Platter will make far less difference than a cartridge for example. Any modern phonostage can work nicely with MM, even Schiit mani for $100. Better cartridge will make any mediocre system better.  

Look at a new cartridge, cable or phono pre first. 

High end / high fidelity sound is about taking extreme care of the signal start to finish. The straight wire paradigm is used throughout the industry to achieve this. Avoid playing with the signal or making the path longer. If you want to improve the sound of your system then I would concentrate on removing any electronics that does DSP or has tone controls. I would switch back to your Sansui preamp and if that is not a great improvement then invest a couple grand in a used high end preamp. This should significantly improve your system far beyond what a turn table change will do. The preamp is the heart of any good system and is worth investing in. The results will then reflect your other components.

I highly recommend Robert Harley’s book: The Complete Guide to High End Audio to orient you to this wonderful pursuit.

Hello,
I like the idea of the Nagaoka MP110. I have it on one of my turntables. $150 is not a lot to spend to have a nice sound. I have a Schiit Mani pho preamp. It works well with the Nag. But I say pass. Too light. Another option is replace the stylus on you 2m blue. That might cost less than the Nag MP110 cart. Both are elliptical. Skip the Rega p2. It’s about the same as what you have with a worse cart. Save up. You can read all of these forums for ideas. You should skip Rega to get adjustable VTA. This is very important not just for fitting but also for dialing in the sound. You have to use shims with Rega. If 600 hours says your cart is dead then replace it with the same thing or the Nag MP110. Save the $850 and more for your new table. I would say the VPI Prime scout. I think you could get one used for $1700. This will cover you for a long time. For the phono preamp I am going to suggest the Sutherland TZ Vibe for $1400 with a new MC cart of your choice.