Amazon Route 53 - billing, did I understand correctly?

Question

Amazon Web Services

I started two domains on Route 53, they took a dollar from the card twice, a few days later, that is, today these same two dollars per card were rolled back to the card.
I didn’t understand a little, that is, that same dollar is not a monthly fee? That is, I pay only for the number of requests? Then why did they steal two dollars?

Answer 1

2 dollars were not withdrawn from your card, but simply reserved. Then they let go. This was done to check the card. This will happen every time you add a new card.
On Amazon, you don't pay for everything at once. Your account is collected within a month from all services and then paid in one payment. You can see how much you will pay in billing.
https://console.aws.amazon.com/billing/home
A domain on Amazon costs $12. But you need to take into account that a Hosted Zone is created with each domain. And this beast costs another $0.5 per month or another $6 per year. Plus, they will consider requests to the domain. But there are already a penny if millions do not visit the site.
For me, it’s not advisable to use Amazon either for domains or for DNS, if for you, of course, such a difference matters. For example, I have 30 domains. If they were on Amazon I would pay $240 more a year. It's $20 per month. For me it's palpable. I'd rather pay extra for the server and add capacity.

Answer 2

"Then why did they steal two dollars?"
if my memory serves me, this is just a check that the card is working, the same for other services