Forgot to add that the EWI-4000s has 2 additional keys. One is for octave doubling, the other is a bit more complicated but allow you to hold notes for harmony during a legato phrase. Also, since it will play without any other device (hardware synth or computer) you can use it to practice your fingering, even if you don't much like the built in synth sounds.

Also, most recently (Feb 2013) I have seen the EWI-USB selling for as little as 209-217 (eBay, bhphotovideo), making it extremely affordable.

Finally samplemodeling has come out with a revision of their Saxophone Family using their own SWAM engine, instead of Native Instruments Kontakt which in my opinion is a lot better for Saxes and the new Clarinet. However, they Brass instruments are going to remain with Kontakt.

Some new demos here:

https://soundcloud.com/dstong

Dan Tong