Want to upgrade my cartridge from 2m blue to black

I would second the idea of NOT ever buying a used cartridge/stylus unless you know the seller well. @chrisoshea

We are talking about NEW OLD STOCK cartridge, not a USED CARTRIDGE? Do you know what is New Old Stock ? Never used, never mounted, like new. Astatic and Glanz are way better cartridges than your Ortofon 2M series, but the cost of the Astatic MF 100 with LineContact stylus from that Japanese seller is just $280 (with free shipping worldwide) and the cartridge is NEW (unused). Nude LineContact stylus, you can buy 3 cartridges for the price of one 2M Black for example. Instead of a spare stylus which is cost $500+ anyone can buy 2 x Astatic MF100 cartridges (with nude LineContact stylus and Moving Flux generator) for the price of 1 Ortofon stylus. Not bad if the cartridge is NOS, don’t you think so?

Do you know how many of us have bought Astatic and Glanz ? Simply seach audiogon and you will find all the info.

I would like to remind anyone who's afraid to buy even used cartridges that you can always return a cartridge with no loss on ebay under paypal buyer's protection (if you think the cartridge is not as advertized), this is simply guaranteed for any purchase on ebay with paypal payment.

I think it would be much more problematic for you to return a new Orotofon if you don't like it than any items purchased on ebay.

Some people just don't want to learn about simple rules for ebay policy and paypal protection. 

Here is a pro-fun suggestion.  It may not exactly be about a direct path to the highest upgrade, but as implied by the budget of the OP I actually think it will in the end be a good milestone in the ascension to higher audio:

(1) Upgrade to an Ortofon 2M Bronze.  It's a noticeable upgrade without being a quality mismatch with a budget turntable.

(2) With the rest of the budget, get a tube phone preamplifier.  Pro-Ject makes a bunch but the most fun I had with a tube phone preamp was the Yaqin MS-12B.  Not the quietest in the world, but the ability to find decent old stock 12AX7 and 12AU7 tubes (which can be pretty cheap) and roll tubes, change sounds, is a ton of fun.  And you can use the thing as a line level preamp too!

Overall there will be some initial sound improvement with the potential for more as you find tubes.  

I am listening to an old NOS Sonus Gold Blue MM cartridge.  I also have an older Pickering XSV 3000.  After listening to these cartridges, I see no reason to entertain MC cartridges beyond my Lyra Delos.  No reason.  I am getting older so maybe my ears are going but on the 1200G these MM cartridges sound just incredible.

@jji666 why do you think a tube phono stage (especially a cheap one) is a good idea ?

A few responses:

(1) I introduced this as a pro-fun suggestion. Tube rolling, especially if one has never done it, is pretty fun. Plus with a relatively inexpensive piece of gear the stakes are low.

(2) "Cheap" is in the eye of the beholder. The OP’s budget implies "cheap" relative to many posters here, but you can get a phono preamp for well less than $100 that technically does the RIAA curve correctly (not that I would...). A $200-$400 phono preamp can be pretty decent and about what is appropriate as a mate for the turntable.

(3) Audio is a journey. While I am usually of the mindset that when you have the upgrade itch you are better off focusing on one big leap upgrade versus a bunch of smaller purchases, analog/phono based upgrades go steep pretty quickly. I was thinking that tube rolling would be a fun experience and allow for an exploration of various sounds based on tube etc.

(4) I did say that the MS-12b is not quiet, so I can see your point. However, short of power tubes that can be much, much more expensive, I found that tube rolling with a phono preamp made the greatest difference relative to rolling in other gear. Your mileage may vary, but that was my experience.

(5) Note the OP's name...

Point being, if the OP wants one of those experiences where he/she wants to relisten to all the vinyl through a new lens, this would be a good way to do it. Spending only on a cart upgrade as with the current TT, and the OP doesn’t have the budget to really do a great TT upgrade and new cart, would likely top out performance based on the TT ceiling. A tube phono preamp is a way to try out different sounds and enjoy an analog feel with old school tubes on that budget.