I am thinking of buying a piano keyboard (not an arranger) just so I force myself to learn how to play the piano better. I am surprised at the price of this unit! Yamaha NP-31, which is newer model than the prior model NP-30. I can buy the NP-31 for about $260! It even can be played using AAA batteries and has onboard speakers and only ways 12 lbs! I have read a ton of reviews and 90% of them are very positive. Anyone have an opinion? Wow, that's cheap.