What are the highest price products so far observed on these platforms?
Books are at the bottom of your paid “media pyramid” and they tend to do the best on ereaders, next up the line would be subscriptions, because if you can sell even a small percentage of your print There’s a $200 limit on the price point for books. In terms of periodicals, Harvard Business Review on Nook is around $100. The Economist is around $125 on Kindle.
You might consider, if you’re selling $597 reports, to put it up in chapters, or as a series being sold separately.