Interesting analysis. But where would higher-end arrangers, like a PSR-SX700, SX900, or Genos fit on these charts? Would they be under "portable keyboards over $199", "keyboard synthesizers", or something else? When I think of "portable keyboards", I think of the lower cost models, the way Yamaha categorizes them, like the PSR-E473. And when I think of synthesizers, I think of keyboards dedicated to direct editing of the sounds, like the Montage, MODX, various Moog keyboards, or my Roland Gaia SH-01.
And if that reflects 2019 data, it will be interesting to see how this all updates after Covid hit, and with the resulting economic changes.