Used Kawai ES3 / Casio Px-320

For those who know a thing of two about digital pianos, does $500 sound like a pretty good deal for this model? The price includes a double X stand and pedal. Could anyone tell me if a CASIO PX-320 would be a better option?

of those 2 I think kawai would be better but I would ask to go lower. Or look at a new Casio PX-150 or Yamaha p-105 for in the 600.00 range.