What To Do?

..and what cartridge are yiou using now?

I have a MM Goldring 2400 and a Project carbon arm.

nantais lenco?

The good news is you can get into some really good sounding equipment if carefully chosen.
 

A really good Phonostage is critical. I would look for something like a used Audio Research PH8 phono stage. This will firmly support a good quality TT from $4K to $30K. 
 

I would look at VPI with a very good cartridge… I think we would need to know your tastes and other equipment to get very specific on that. 
 

if you could spring for a bit more I think you could really get into a really amazing system… say ~$5K TT and $2.5K cartridge + the ARC PH8 (this is a really sweet spot… I owned one for years… I now have a ARC Ref 3… which is better… but at also double the cost).

So basically, every responder on either of the two parallel threads you’ve started is recommending stuff he owns or has owned. The result is confusion and some faulty advice. That’s no way to decide how to spend $12,000. I’d advise you to keep your powder dry and do some aggressive listening so you can make up your own mind with confidence.