I cant really compare to old models (I just don't remember).
But just take a look at these ridiculous prices in Israel:

Tyros 4 (w/o speakers): 17950NIS = 5279$ (USD)
Tyros 3 (w/o speakers): 16500NIS = 4852$
PSR-S910: 5950NIS = 1750$
Ketron Audya: 24000NIS = 7058$
KORG PA1x (yes, 1x): 17400NIS = 5117$

I bought my PSR-3000, almost 5 years ago, in 9000NIS = 2647$.