@luisma31
If i were you i would buy a better MM cartridge for this old Technics turntable, i would definitely rewire internal tonearm cable and external phono cable. Actually i've done that before with my pair of SL1210 mkII (added kab fluid dampers and isonoe feet, complete rewire with cardas internal and zu mission external wires/cables, but unbalanced). I was very happy with result, the most important is cartridge, the rest of this upgrade is very cheap, but you need superb MM or MI cartridge with advanced stylus profile and impressive sound quality. There are many of them available NOS. Over the years i've been buying all of them.
It is nice to change a turntable too, but this is much more expensive and you can do that later when you will have a perfect cartridge to install on better Technics turntable. If you don't have the real killer cartridge then i don't think you have to start with new turntable.
BUT if you have a budget for SL1200G go ahead, it can be your last turntable for the next 30 years :)
P.S. Discogs is fine to buy records, i prefer original pressings from the 70's as most of my music is from that era. I don't like re-issues.