Looking at the N1 単語ターゲット2000 book, the book costs 1700 yen, and they're selling it for $27. In dollars, it costs around $21.25 if you bought it in Japan, plus there would be shipping from Japan, which can run around 30-50% of the price, depending on delivery speed. (From SAL->EMS, that's been my experience in the cost of shipping.) So $27 sounds pretty fair, actually. You could always check bk1/honto, kinokunia US and thejapanshop.com as well. Kinokunia is pretty cheap, with free shipping if you buy all from the same branch and spend over $100.
As for particular books, I'd be interested to hear others' opinions as well. Here are mine:
I have the N1 versions of 完全マスター and 日本語総まとめ. I also have the old 1級 version of KZM 文法 from my N1 grammar class at Yamasa, and I prefer it because the old version has more grammar bits in it versus the new one. About half of the stuff we studied in my class wasn't in the new version of KZM grammar. It could be just sample error, or that the new book is better targeted, but there it is anyway.
The new KZM grammar is a good book for review, but I wouldn't necessarily use it for learning. I'd get the old version for that. But I could be out in left field, and expending unnecessary effort, learning stuff that won't show up on N1. All I remember from my N1 exam was that it didn't feel a lot like anything I had learned up until that point.
The KZM 語彙 book is interesting. Not sure if it duplicates the NSM 語彙 book, tho.
The other books in the new KZM series are all good. About the same as the old versions, except cleaned up a bit, and geared towards the new exam.
The N1 version of 日本語総まとめ is pretty much the same as the N2 version. Once again, no explanations of grammar, just exercises and example sentences with English translations. Not really sure where it is on completeness vs. KZM 1級 or N1, but it does have a lot of material in it. I didn't really like the lack of explanations/definitions in the N2 version, and I don't really like it here, though. It's kind of annoying.
Either way, I would pick up both 読解 books, mainly because 読解 always kills me.
The first book I mentioned, the 単語ターゲット book, is good, but not essential. You're going to cover a lot of that vocab in the other books. I might get it later to check to see if the first 2 missed anything. It's a good book, though, in that it goes in descending frequency of appearance on the exams. That's pretty darn handy.
My final recommendation would be the ドリル&ドリル series by Unicom. They have books for 文法 and 聴解・読解 for N1. They're crammed full of practice problems, and the harder ones have lengthy explanations in the back. I loved these books for N2. These are for after you've learned all of that other stuff, and just need to practice like mad.
Edited: 2012-06-20, 10:14 am