As a publisher, or even more as the photographer who did the work, why would I price a book at a point that puts it far out of the reach of most consumers. I'm not saying to make it a $3.99 paperback at Walmart. But at that price most bookstores won't order even one to put on the shelf, and it's out of the budget of all but a few large libraries. Only a select few with plenty of disposable income and an interest in the work will bite. That leaves a pretty narrow group of people to sell to. I can understand a special limited edition aimed at collectors if there is enough interest. But is $50-$75 too hard to do? 1000 copies at $50 looks better in my bank account than 10 at $300.
And I bet you can get a digital copy off a torrent site before it's even released.