Maybe a Kurzwiel SP76 will suit you? It's way under 1000. I don't know how much control you need (sliders, knobs and buttons), but just to open your mind up a little, you could go for a good Yamaha PSR and add an Evolution UC-33 and a small Midi Merge box.

There's many ways to go actually, since weighted keys are not a main issue for you.

But weighted keys will allow a piano player to be much more expressive.

Best wishes