Turntable upgrade, tweaks, or stay put?


I have a music hall mmf-7, stock with goldring eroica and project speed box. Rest of system: Wilson audio Sophias, Musical fidelity KW 500, Musical fidelity Trivista DAC, and Musical fidelity CD player. I really enjoy the mmf7 and have no real complaints. However, I know it is the weakest link in my system. I wonder how much better it could be. Do you think I would have to spend $5-6000 or more on a new tt to get significantly better sound? Any recommendations? Or would some tweaks be smarter? Or just save my money and buy more records? Thanks in advance. As I said, I like my mmf7, but wonder if I am missing out by not having something of similar quality to the rest of my system.
arsh
I also have the possibility of using my father's VPI scoutmaster as a replacement. How would it compare with the MMF-7?
Look for a used vpi classic table. The vpi will be a good leap ahead of the mmf-7. And you have enough cash left over for more vinyl. That's a no brainer good luck.
I had an MM7 and once I changed out the stock Goldring for a Lyra Delos, this TT came alive. The MM7 is good enough that it will respond to and take advantage of an upgrade of cartridge. Recently, I bought an Ortofon 2M Black MM cart and this is a stunner for much less $ than the Lyra. I'm simply saying that I would not be too quick to judge that it is the MM7 that is the limiting element; it is a solid and very quiet table.
Thanks again for all the good ideas. I did borrow my father's old scoutmaster. It hasn't been used for most of 4 years. It was professionally set up. I put it in my system and put on a record that I know well, and it sounded very distorted. Since I don't think the setup has been changed, I am assuming this is a problem with the cartridge (grado reference master). Both channels play but with severe distortion. I don't remember if this was a problem before in my Dad's system; it could have been and he never got it fixed. Should I get a new cartridge? Seems I can't catch a break here! Also, I think the KW500 phono stage should work for this cartridge. It was fine with the Eroica.
The Grado has twice the output of the Eroica. Does the MF have gain & other adjustments?