I would definitely first ask one of the dealers on the forum like George Kaye or Dano for a competitive price on the PSR2000. If the price isn't competitive, I would go with Music123.com. Their price would include shipping, so overall you would pay less.

Several years ago, I purchased a PSR740 from this eBay member. As you might recall, the PSR740 didn't come with an adapter. I got the keyboard for about $800 plus shipping. The keyboard had a USA warranty card inside. When I needed a repair, I got free service at an authorized Yamaha repair center.

Nevertheless, it does appear that this dealer is taking the adapter out to make money off uneducated customers.

Maybe he used to be authorized and no longer is.

Beakybird