As long runner MGs fan, over 20 years, I owned MG 1.5 and then MG 3.6 and finally MG 20.1. I can say that MG 20.1 is so much superior above other two models that it is easy to understand price difference between them. Frankly speaking sound performance of MG 1.5 was always more pleasured than with MG 3.6, but MG 20.1 is completely another level. If you can effort MG 20.1 than this is the way to go. In Europe price of new MGs is really high compared to USA market, more like double. But there may be solution to find used, not to old pair at moderate price. My preferred music is as well acoustic jazz and some classical and looks like that MG 20.1 most probably matching your described sound preferences.
Regards
Regards