I would happily pay twice that price, or maybe more, for a good-looking version.
I agree with mathgeek, and would like to encourage you to at least do some kind of poll based on a quote from a decent printer. I think you would be pleasantly surprised.
I'm not rich and don't go around throwing $100+ at random whims, but man, we are talking about an impressive tribute and memory of the games I, and many of us, love. A good bunch of the games you cover were an enormous influence during many years in my life (and I still come back to them regularly). It would be one of the most cherished books in my library. Although I love books, these years I'm limiting my physical book purchases to three or so a year due to lack of space, but I would get this one without even a second thought.
I don't want to believe that I live in a world where this book can't get a physical edition to make it justice. One way or another, it must be done.
PS: in page 79, the caption of the last screenshot of Ultima IV seems wrong. I think it was miscopied from a screenshot of The Bard's Tale.
Like a few here, I'd gladly pay $120 or more for a two volume hard cover version. Do consider doing a kickstarter or other form of crowdfunding. I've been reading the book and it's a real trip down memory lane :)
And in term of taxes, as someone living in Japan on a temporary visa in Japan, you do not pay taxes in Japan on income from abroad that does not get sent to Japan. I'm not sure about the Brazilian side of things but you might qualify as non-resident and in that case not be on the hook there. Of course, consult with a professional or read the double taxation agreements (which is a dry reading) but it's likely to not be too complicated in your case.
Heh, I'm still remembering this line: "[...]but if all goes well we're talking of a colored 480-page paperback for about $25-30. And that's printed on-demand via Amazon." ^^
But really, it is as mathgeek says. You are underestimating how much people are willing to pay for this. Though, as you said in the blog post, it's all future-talk at this point.