The number above doesn't sound right.
This is what I found (US site):
eBook Royalty Options
You can choose between two royalty options for each of your eBooks: the 35% royalty option and the 70% royalty option.
There's more on
eBook Royalty Options.
-- Amazon is a market place, and the highest volume of eBooks sales is through their platform.
And this makes it more clear (except you can't price a book at less than 0.99, except by *selling your soul* and *hanging from monkey-bars*):
The royalty rate you get paid from Amazon for eBooks is 70% of the retail price if the price of your eBook is between $2.99 and $9.99. If your book is priced between $0.01 and $2.98 or greater than $9.99, you get paid 35% royalties. Thus, most self-published authors prefer to price their eBooks between $2.99 and $9.99 on Amazon to receive a higher share of royalties. (from
How Self-Published Authors Get Paid for Ebook Sales | TCK Publishing).
I am self-published, so choose to be in the 70% royalty option for some, and the 35% option for others (higher read-rate). I don't have any books over 9.99, and I don't have books with costs for transmission (usually involves pictures, but sometimes publishers upload documents with too much formatting, or the same formatting as the pb, which effectively multiplies the 'weight' of the finished product thereby invoking transmission costs). I also use one of two aggregators, rather than setting up publisher profiles on all the platforms (I use Smashwords & D2D, and currently trialing Google. D2D is only because they have a link to sell on Amazon [The 'zon doesn't recognise my bank]). Amazon has the most subscribers/buyers (I'm only referring to books). Using Amazon to sell books is making use of the highest volumes sales platform.
I think your publisher isn't playing it completely straight. Amazon may be paying the 70% and then the publisher is taking their percentage (25% -- I thought it would be 15% for publishers; check your contract) from the full price. Your book was in 70% price category ($7.20 in Australia today, $4.99 USD).
I don't publish exclusively to Amazon (not my biggest sales platform), but they have the reach to new readers so they can't be dismissed out of hand. Kobo is now creating a Kobo Plus to copy the structure of Amazon Books (for subscription readers, haven't checked the exclusivity criteria yet).
However, my comments don't include pb published through their platform. I use Ingram Sparks, despite the rigmarole (better reach, and) because the discounts are ones I can set, not the marketers/platforms (unless they are cutting into their own take).
It's worth checking. A lot of authors get annoyed by the lack of information/facts from their publishers and end up going indie if they find obfuscation and other forms of BS.