the reason your dealer pushs the XP's because the market of this keyboards are seems very slow this days.as you have noticed on
www.rolandus.com that you will get USD100 cash back if you got XP-60/80.for the VA-7 it's in CK devision and may be your dealer are not a CK dealer.
my opinion is that you go for the VA-7 if you don't like to spend money after buying your keyboard for any other options.the VA-7 have all you need and you wount need any thing to support the keyboard.plus you got a sampler, 128 voice polyphonic,and a huge collection of nice sounds and drums that will fit your needs 99%.plus it's an arranger so you got styles incase you want to play by your self.and many other things that you will like once you get it.if you want to go for the XP's I suggest you wait because I think that very soon roland's new workstations will come out(may be XV-61/76 or RS-7/9)because the xp's are old now

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hope this helps
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vic