I don’t think it would be crazy to host the full exhibition in New York City. There are thousands of US fans who would travel there. I hope they know that it’s feasible, or that DH is doing its best to court them on the idea.
Starting today, a number of items sold at the exhibition are available to purchase online, through the website of the mall where the pop-up store is located. It will close on November 19. It's likely all but impossible to use that store for people living outside of Japan without using a broker, but still, worth mentioning.
The Artwork of Berserk book is indeed available there for 3850 yen, about $25. However as Aaz noted, there is no international shipping. So this probably isn’t what was meant by the previous announcement that certain items would be available for online purchase.
Quite a bummer that they’ve held international fans out of the loop for so long. It’s been 2 years now.