I can understand the need - desire? - for 76 keys, but other than that shouldn't the inspiration for playing come from within ? ...
When I was first taking management courses we were told that money is the lowest motivational factor for a person's performance and that pay increases only motivated for a very short period of time ... It took me a while to understand that ... I feel the same way about keyboards ... yes, they may motivate you initially, but how long does that last ?!?