I like many here I cringe at using my $5K cartridge on an LP that saw weekly use in High School. I have not dared to play any of my 78s on it either. So, I have been contemplating a new 2nd turntable. One that plays my 78’s and other less audiophile quality stuff. The thought of two tone arms interests me.
Simply look for SP10R or earlier SP-10mk III or cheaper SP-10 mkII they are all designed for use with 33/45/78 records.
The SL1200G also play 78rpm.
Should I get good MM turntable to play the less pristine LPs? If so, which one? Should I get a turntable with two arms so that I can play 78’s on a well paired cartridge?
Definitely, and with really good MM under $1k from the golden era you will be surprised comparing it to your $5k MC :)) Read this.
Without breaking the bank you can find a decent MM with spare styli for Stereo, different era of Mono, and 78 rpm (Pickering and Stanton made all kind of styli for their MM cartridges).
You can play 78 on Technics with MM cartridges, all you need is heavier headshell and stylus designed for 78 rpm.
If you want to be purist you can buy heavy tonearm like FR-64s and special mono cartridge for 78 rpm like Miyajima.
Technics SP-10r (or SP-10 mkIII, mkII) can be used with two tonearms, but tonearm must be at least "10.5 inch or longer (avoid "9 inch tonearms for this drive because of the short mounting distance).