Wow. 10 cents per message, that is not cheap.
If you think in terms of how much your time is worth:
- How much of would it cost you to forward a 2FA message to a team mate?
- Maybe two messages, if the first one expired by the time they saw it?
There's the ancillary cost of the frustration if something goes wrong, as well as dropping whatever you were doing to do this menial task.
This has been fully automated and managed with SMS to Slack.