Keyboards

Hello fellow tuners,

I'm a bit of an amatuer. I've been working with a Kurzweil 2000, composing
music based on
11 & 13 equal (ocassionally 11 & 13 Carlos Just?).

It's been a blast!!!

Now I'm hooked, but I need a keyboard that I can tune. The Kurzweil is
pretty easy once you get the
hang of it. The main problem with the 2000 is that sequences are
uneditable, I believe. Also the
2000 I'm using cannot sample at this time, although the manual says that
sampling would be available
at a later date. Can this keyboard sample.

I've been told I could buy one of these at about $500 - $600. True? (I'm a
student.)

Any suggestions for a superior keyboard on the cheap?

By the way I'm mainly a Mac guy, although I have a PC.

Thanks forum.