With or witouth onboard sounds?
Mobile or not mobile?

You can not go wrong with most Casio's
PX5s and PX360 come to mind..
Great keyfeel and good quallity piano sounds onboard..

Unless you want to have aftertouch too..


and then there is the midi keybeds witouth sounds, you might even find a Kawai VPC1 used for just under $1000. or the Roland A88... great keyfeel but just as expensive as the Casio PX-5S.


But for a better advise, i would love more information on how you mean to use this 88 keybed..