I charge £1/zone/month for DNS-hosting, and while most of my clients only have a single zone there are people with 50+
DNS hosting can be cheap (free if you use cloudflare, etc), or very expensive. My prices give me a 50% margin over the raw AWS Route53 costs, but the appeal is that I store records under revision control and let you make changes using git:
AWS charges you a flat-fee per zone, and then additional-fees based on volume of queries. In my case I don't host any domains that go over the threshold where it is billed for - but if I did those costs would be offset by the profit of the other low-volume zones.
But what caught my eye was DNS Hosting: 5$/Month? Maybe it's a typo, shouldn't be more like 10$ per year to host a domain and its DNS?
Anyway, thanks for sharing, very interesting.