Ok, I see you've added some text in terms of "Buy your copy to read more" which is a start (although it's probably too far from the email capture for people to associate them, and it doesn't stand out from the rest of the body text). But if you want to be transparent, include the pricing there. And if I'm really going to think it's transparent, don't ask for my email without a) really needing it (i.e. as part of a transaction I've signalled clear intent towards) and b) making it clear how it will be used (in normal sized type!)

For me, the bottom of that page could be something in essence like "Buy the book now for a 'pay what you want' price and get immediate access to X content." I'm not sure you'd need much more (email can come as part of that process, and I'd ditch the bitcoin only payments for certain levels - just simplify it and if you need the bottom price to be slightly more to cover card fees, just increase the price to cover them).

Put it all front and centre - if it's a commercial book, that's fine - don't try and hide it, show the value it has and make it very easy to give you money.