If your interested in accoustic piano voice, I am very impressed with the Roland EP-760, but this is not in the same price range as the Casio WK3000. A true die hard piano teacher will encourage you to purchase a weighted keyboard. I'm not sure if the EP-760 is weighted or semi-weighted, but it feels and sounds like a piano to my ears. The other voices on it were crap. It also has 76 keys. You are going to demo these keyboards before you buy right?
Starkeeper