Why are the prices of your books different on amazon than they are on your website?
Like any retailer of any product (not just books), amazon has the right to sell a product for whatever price they want, higher or lower than the list price, as long as they pay the manufacturer the "correct" list price that was invoiced.
So if I list a book at $12, amazon is free to sell it at $6 or $19, as long as they pay me $12 (minus their stated commission). In the first case they "lose" money, in the second case, they increase their profit.
Why / how do they do this?
First, no human beings are involved; it's all algorithms.
Two, the folks at amazon themselves can't explain it, or prevent it, except by manual tinkering (overriding manually a price) but then the algorithm "fixes" it again later so it's a quixotic battle.
The *theory* (I insist it's only a theory) is, the algorithm looks at all the Marvel, DC, etc comic books, and the page count, totally ignoring the actual cost of printing in color vs b&w.
So if it sees me sell a 48-page color book and a 136-page b&w book both for $12.95, it decides I'm "wrong". The 48-page book should be sold at $6 and the 136-page book at $19, based on the hundreds of all the other "similar" comics being for sale, and it "corrects" my prices.
That's the "theory" anyway.
Needless to say, I'm powerless to fix it.