I'm confused bout the rtk volume 1, I went on Amazon and ordered the totally blue book, but I've noticed that there is the book which has a blue and white cover. (blue on bottom, white on top.) So which one do I pick, is there any difference of the two books?
Plus the blue and white version has more pages....Why?
P.s: I ordered the totally blue version of rtk vol 1, but still hasn't shipped so I might cancell it, if anyone tells me theres a difference between them.

I did a quick search on amazon and google and it seems that the one with the blue cover that can be found here: http://www.amazon.com/Remembering-Kanji-...408&sr=8-1
is the fifth edition and the one with the two colors is the fourth: http://images.google.com.br/imgres?imgur...R%26sa%3DG
The difference between the editions is that there are some mistakes in the fourth edition that have been corrected in the fifth and a few (8, I think) keywords have been changed.
I've seen some people bash the fifth edition, but there are also people that complain about the mistakes of the fourth. So ultimately, it's up to you to decide which one you choose. I myself have been using the fourth, but I think that no matter which edition you use, this is a great book that will be invaluable to your Japanese studies.

So the blue book is the newer one of the two. Why is the fourth edition more expensive? Is it because it has more pages than the total blue book?

It's because the 4th edition is out of print. Out of print books sometimes cost more simply because they're out of print.

It doesn't matter which edition you choose, the method is essentially unchanged. The only things changed are detail-things. Some people don't like the crummy binding of the 5th edition, but I look on my mangled copy with pride, because I sucked every last drop of knowledge out of it.

Edit: spelling.

I would buy the version of the book that isn't ridiculously expensive, but has pretty much the exact same material as the other version of the book.

Arigatou minasan!