[jacquesm]

If you are at all serious about piano I would recommend getting an 88 key keyboard with half decent keys. Anything less you'll outgrow in the first few months and you will be learning to properly orient yourself. On a smaller keyboard you're going to mess up your 'South Sight' and your 'North Sight' because you will train yourself to orient on the edges of your smaller keyboard. As soon as you sit down behind a proper piano you'll be confused.

Good keyboards aren't expensive any more, the simplest Yamaha, Casio and Roland that qualify for serious study are all around $500 if you shop around a bit and if you go for second hand can be had for half that. You'll very quickly match that in lesson costs so if you can afford the one you probably can afford the other.

You don't need sequencers, aftertouch, built in DAWs or controlling an external one etc, those are not aimed at piano students. Can be fun but complete luxury.