Nah, if you don't need list management you're definitely better off going with something a little bit closer to the metal. We actually keep a price guide for comparing MTAs here (https://buttondown.com/comparison-guides/esps). I do happily recommend Postmark; they're a little bit more expensive than their peers but are worth it, IMHO.
I think some of that pricing is off. Sendmatic at least seems to suffer from some decimal placing.
Very cool page and very cool of you to do. Good luck with the biz.
(I've migrated a domain from .io to .com, I can relate)
I'm a possible customer, so I looked at the service and its pricing page and… I'm not sure if this is a service for me. I send both transactional and non-transactional E-mail, but I don't need "list management", just E-mail processing. Buttondown would be $29/month + $50/month for whitelabeling, while Postmark would be $15/month. Am I missing something?