While I failed at 2012, I plan on using my supplies to start over and do 2013.
I do not plan on taking a photo or journaling every day. I snap photos and jot things down as they come to me, and I like to tell the story of the WEEK, instead of each day. So if something important happens one week, I give that story more precedence in the spread for that week (maybe 3 photos and 4 journaling spots, for example).
I think a lot of the traditional style albums end up being 2 binders full, but I'm sure someone else can chime in. It depends on how much you save/embellish/etc. I know some of the PL CT end up doing 3 binders.
That page protector that you linked to is meant to fill half a week. 4 photos and 4 journaling cards, and you would traditionally use 2 of them next to each other to tell the story of the week (one of the 4x6 slots is for a "title" of sorts, to specify what week it is, or the dates). There are 60 page protectors in the Big Packs, and you only NEED 1 big pack. You use each slot twice. The front for 1 week, and the back for another.
There really is no "traditional" Project Life anymore. You certainly can use it for a P365 (and then you would take a photo a day, and journal each day) if you want.
ETA: Check this out
http://www.beckyhiggins.com/products...ng-started.php
And this
http://www.beckyhiggins.com/products...oject-life.php