Which $100 cart. is best for I.G. distortion?

Well, you used to be able to get the Audio Technica AT440MLa for $100 or less, but that's becoming difficult. The one source that still prices them at $99.95 (lpgear) is back-ordered. The other places are charging more like $150-200. I have no direct personal experience with the AT440MLa, but several user reviews at Amazon specifically mention that the AT440MLa eliminated inner groove distortion they were getting on several other cartridges.

I'm using a Denon DL-160 on my SL1210 M5G, and am very pleased with its inner groove performance. It can also depend on how you align your cartridge. The alignment jig that comes with current SL12x0 turntables favors a better alignment in the inner groove area.

And for what it's worth, both the AT440MLa and Denon DL-160 stylus tips are nude square shank diamonds.

AT125LC is similar to AT440MLa. That's what people say.
AT125LC comes available on ebay from time to time. I got two of them new at around $60~$70 each.
It outperforms Shure M97xE.

Dear Mika: Thing happen is that that cartridge is a very poor tracker ( and you can read it on the Ortofon specs about: tracking ability ).

You can do a lot better with the Ortofon Super OM20 or the 530 MK2, both with very good quality sound performance.

Regards and enjoy the music.
Raul.

The Shure should work fine. The stabilizer brush solves a lot of tracking issues.