Upgrade cartridge or turntable?

speaking as former Rega P3 owner I don't think you're going to recognize a transformational step change via cart replacement alone.  I'd consider applying your $2000 TT budget toward an upgrade on the used market.  The P3's inability to provide really solid isolation is going to prevent you from fully recognizing the benefits from any cart upgrade IMO.

As a frustrated and another former  Rega RP3 owner, I would unabashedly recommend a different turntable.  Aside from any isolation issues, the lack of an easy VTA adjustment for different cartridges is just plain arrogant.  Some <$600 turntables have a VTA adjustment process with simple set screws at the base. Some carts will not even mount due to their own height.  

There are tons of <$2000 tables out there Rega.  BTW, the Ortofon 2M Blue is quite good IMO, but the market for REALLY good, fairly inexpensive moving coil cartridges has expanded rapidly in the past few years.  

Get a new stylus and save more money. Let us know when you get to $5000.

I'd throw a Dynavector 20 XL or whatever suits your budget on the table - the Planar 4 can definitely handle a big cartridge upgrade no problem.

According to expert advice I ignored in my youth, turntable first, tonearm second, cartridge third. I ignored this advice, to my cost. For one thing, turntables and tonearms don't wear out.

Another thing to consider is bang for buck. There is a tonearm which is within your budget which punches far above its weight (and cost): the Trans-Fi Terminator (yeah,  I know, but I didn't name it). Air bearing sled, and solid, intuitive, repeatable adjustments just like tonearms costing 10 or 20 times as much. I have two of them, running MC cartridges with an air bearing TT.

Put the balance into a record cleaning machine - I like ultra-sound. Works for me, but YMMV.

Get a new stylus and save more money. Let us know when you get to $5000.

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According to expert advice I ignored in my youth, turntable first, tonearm second, cartridge third. I ignored this advice, to my cost. For one thing, turntables and tonearms don't wear out.

Mike and Terry are right. The challenge is making the leap to buying turntable/arm/cartridge separately, when the combination you might ultimately want adds up to $10k or more. 

The tried and true approach is to find the very best table you can afford, and run it with a budget arm and cartridge, until you can afford to upgrade to a really good arm, and then finally cartridge. 

This way you spend the big money on things that really just do not wear out, so they are keepers and nothing is lost in the resale/upgrade treadmill. 

Another beauty of doing it this way, its almost impossible to find a turntable or arm that expensive that's not really, really good. VPI and Rega can sell based on ads. Nobody bought an Origin Live or Graham arm based on an ad. Their "advertising" is word of mouth. 

Take your time. There's a lot more going on than just sound. Another big factor with turntables is the way they look, feel, and function. Pay attention to all those details, plan out your path, take your time.

Miller is dead right about the look and feel. I use top line vintage test equipment like oscilloscopes and signal generators just because they look and feel better. It makes a big difference when you look forward to fiddling with things, rather than just enduring the necessity of doing so.

And, as Miller also says, "...take your time."

Its really important. Something like say a cartridge, who cares what it looks like? Really? I mean okay maybe for like three seconds. Then reality sets in and what you really care about is can you set it down where you want, like right at the beginning of a track, which comes down to seeing the stylus or some other visual reference, AND in combination with that how the tone arm works- with the cue lever or does it have a finger lift and will you use it?

These are just a few of the practical considerations few people think of until they are living with it, by which time its too late. Most of what's in the higher ranges is awfully good. But there's a whole market segment that seems devoted to filling the needs of audiophiles who to judge by their choices seem more latent masochist than audiophile. Why set yourself up for that? I mean, unless you like that kind of thing. Not that there's anything wrong with that, imagine Seinfeldian eye roll....

I have a Rega Planar 3 turntable with an Ortofon Blue cartridge which has served me well. I’ve had them both now for two years and am around the 1000 hr mark which in itself draws debate.  

Actually if your elliptical stylus has been in used for more than 1000 hrs then you've been listening records with a worn needle for some time (at least for 400 hrs). Upgrade your 2M Blue with a stylus from higher model in this series such as Black or Bronze, get a stylus with better profile (Shibata or Line Contact) and it will be a significant upgrade at the lowest possible cost in your situation.   

I’m looking for opinions on either a cartridge upgrade, or a turntable.  Can go to 2000 for TT, also considering MC cartridge which would involve a new phonostage.  Let’s hear it.

Do both. It is more fun. With $2000 for a TT you'd better look for new Direct Drive Technics SL1200GR or some killer vintage direct drive turntables. 

I can't speak from first-hand experience but have you considered various mods out there for Regas? GROOVETRACER® SUBPLATTER as an example perhaps in combination with tonearm+isolation-feet+mat upgrade from Funk Firm, all which together, at least based on online reviews will give you sound quality at multiples of the upgrade cost.. just a suggestion.

@miketee Couldn't agree more with you on the clunky VTA adjustment by spacer only.  Such a ridiculous design.  Then you have the lack of azimuth adjustment.  Honestly, why would anyone consider upgrading a cartridge on a P3 if it's nearly mechanically impossible (due to flawed table design) to set up the cart properly????

Honestly, why would anyone consider upgrading a cartridge on a P3 if it’s nearly mechanically impossible (due to flawed table design) to set up the cart properly????

This is why he could upgrade only the stylus, but the cartridge was sold with this arm/turntable, no need to adjust anything.

In my opinion Rega turntable is a cheap plastic toy with a belt. My strong advice is upgrade to Technics direct drive, SL1200GR is under $2k new with warranty and slightly cheaper if used. Same Ortofon 2M can be used and properly adjusted on Technics tonearm like any other mid compliance MM/MI or MC in general. 

Lots of great and practical advice here.  I have spent extra on isolation platform and power conditioner after I purchased the TT because frankly, it didn’t sound too good. Those two items were more than the cost of the Rega, but they did make a huge difference.  I did find making adjustments with the arm difficult, and being that this was my first jump to a better quality table was annoyed that there was no ground wire, being that I was having noise issues that were improved by the conditioner.  I looked into a new stylus, but it was almost as much as a replacement cart. I may look into the stylus replacement from one of Ortofon’s other cartridges although it will still be close to a new cartridge.