Amazon is definitely the company we all love to hate. It screws up or uses suboptimal practices a lot. But it does have a huge audience, and it is the only reason self-publishing as we know it exists in the first place.
Your actual mileage may vary, but indie authors sell far more ebooks than they do print books. With a minimum print run of 24, it will probably take you quite a while to sell all of them. With Amazon (and probably some other options), you're dealing with genuine POD that doesn't require a minimum quantity. That is usually pricier than offset. But here, offset seems to be more expensive. $5.28 for a 16 page book? I can get an Amazon print price of $2.37 for my 116 page novella (which is 6 X 9, a size that would push the per book price to $5.60). Speaking of which, we ought to talk about why the quote calculator doesn't enable you to change the number of pages (and spine width). I thought maybe that was a glitch on Chrome, but on Firefox, the page does the same thing. Is this a ploy to force you to call customer service just to get an accurate quote? Anyway, you probably get some reduction on price per page as the book gets longer, but enough to compensate for the increased number of pages? Probably not. So we're looking at something that becomes substantially more expensive than Amazon.
Also, did anyone else notice the extra shipping charges? As far as I can tell, paperback distribution is done by the author. The books get shipped to you, and you need to ship to distributors. I know, that sounds insane. But searching for paperbook book distribution gets results for book printing and a couple of 2018 blog entries that talk, among other things, about how to arrange for publication on Barnes and Noble (as well as a weird description of seller accounts on Amazon, as if KDP didn't exist, which it did by that point).
When one adds in shipping costs, the per-unit cost goes even higher. (Note the cheap ground shipping rates apply only to orders of 100 or more.) The situation reminds me of the pre-self-publishing horror stories of people whose garages are filled with books they can't unload. In this scenario, you can at least get rid of them--for a ****ton of extra shipping charges. And then some distributors might charge fees over time for warehousing inventory for you.
It sounds to me as if DiggyPod is taking a process that is simple on Amazon or Ingram and making it several orders of magnitude more complicated and expensive.
With Amazon, you have no upfront costs for printing or shipping. Print costs get deducted from your royalty share, but you never pay anything out of pocket. And the print costs appear to be far cheaper.
Ingram has really good distribution. Amazon has okay distribution (not much bookstore possibility, for example). DiggyPod appears to have DIY distribution for print books.
Many people recommend Ingram for expanded distribution and Amazon for Amazon only. Being lazy about that, I just use Amazon. But indies who actually get significant presence in bookstores are rare, regardless of distribution, and almost all of my sales are on Amazon, even though I have their expanded distribution option. Writers need to experiment to find the best fit for them.
Anyway, DiggPod seems cumbersome at best--or am I missing something?