IAs far as the money. For example, the soprano saxes are incredible. Google the price of a Selmer soprano sax. The sax alone costs about the same as what we can buy a T4 for.
That's an interesting why to look at it Scott but I think a Tyros 4 (or any other keyboard out there) can only serve as an approximate assimilation of an acoustic instrument. Any pro sax player playing a Selmer will sound better and achieve results not possilbe on a keyboard.