Data Point
I bought a Pam C in Oct 2011 for less than $1000. It was in a red box (in pretty crappy condition) but didn't have the companion book. The cards were mostly in good condition, but the front of the King Wands (? - I'm at work and the deck is at home) is considerably darker than the rest of the deck as if it sat out in the sun for an extended period of time. The backs of a couple other cards are similarly dark. And I think that one card has a little bit of the front of it missing. A number of the cards are cut horribly off-center too.
The deck in question sounds in much better condition than the one I bought, so I could see it easily going for somewhere between $1000-$1500 depending on who's watching the auction and bidding at the last minute.
I won my Pam B for a ridiculously cheap price, I believe, because the auction ended on the Sunday of a holiday weekend (Labor Day, I believe it was). So timing can also be an important factor in how much you get for the deck. Don't have the auction end too early or too late in the day and don't have it end during a holiday weekend.
EDIT: The box for my C is green, not red.