Casio CT X700 is $175 US, it is a 61 key arranger type keyboard with a synth type key action
Casio CDP S100 is $480 US is their lowest priced digital piano with 88 hammer action keys.
NP12 $200 US, 61 key digital piano
PSR E360 $199 US, 61 key arranger type.
There is a distinct difference between a keyboard and a digital piano and if it is a digital piano that you seek then do look at a used Yamaha, Roland or Korg within your budget, if you see anying post its make and model number here and no doubt someone will suggest an action for you to take.