Well, there's a "middle-of-the-Rode" (uuugggh...) solution no one's really elaborated on, and maybe that's because it's been bypassed by the NTK: The NT2. I have one and it works wonders on my voice (that CAN'T be easy) and it sounds good on acoustic guitar. I've also used it with success as the single mic on hand drums (djembe, congas, bongos).
Now, the reason I bring this mic up is, you can get them used quite easily, it seems ... I got mine for $300 about a year and half ago. Not bad. I don't know what they're going for used now but they may be worth looking into. It's not the kind of mic that works for every voice, but to my ears it's MUCH better than the NT1. I can't comment on how it'd stack up to the NT1000, NTK, or Classics. I imagine at least the NTK and Classics sound better, but then they cost more.
Of course, with any mic, it helps if you can get a chance to demo it (even in the store) before deciding. It's not the ideal place to demo, but when I heard the NT2 I knew I liked it better than the others I tried: a CAD one (don't remember which), an AT4033,
an AT4050, an AT4047, and some others.
I don't think it's that good on upright piano; I tried it there and have better luck with a pair of Marshall MXL 603Ses. Those are cheap and good, BTW.
There are other vocal mic manufacturers, too. Is there a reason you need a Rode mic specifically?