Scott, you said:
"The price is NOT similar as far as I know. The price of the XD9 is more than twice than the PSR2000.... If you know of an XD9 which sells for the same price as PSR2000, PLEASE let me know"

More than twice?? But you may see at Synthplaner these prices:

XD9: 1122 $
PSR2000: 1111 $

Only if you considere XD9HD, it is more priced (but PSR hasn't HD), but not "more than twice than PSR". I think you include also to buy an independent vocal harmonizer (XD9 has't it).
Or perhaps your dealer sells XD9 at higher price than PSR2000...