Ask in the FAQs then - I'm sure Andrea will be happy to answer. I've asked him about the other two books already.
But as Bonnie Cehovet says in the video - it may be too niche to make it without using this method to at the very least get a lot of attention. Heavens - they've already sold at least 150 copies. That has to be reassuring when you are trying to bring something out that you do NOT want to see remaindered in a couple of years.
And the price - well, in a store, think how much you pay for a full colour book that size. Kaplan black and white vol 1 is listed new at £23; the colour 2 and 3 are £25 and £28.70; 4 is £29 and change. The standard price for this is £14. A bargain, I think - and one which probably wouldn't be possible without crowdfunding. I'm sure it will rocket up when the book makes it into stores - but backing it gives the chance to get it for less - just look at some of the excellent decks that have been funded this way, which cost way more afterwards (I can think of two in particular I neglected to back which were twice the price when they went on sale to non-backers.)