The trick with Wasabi is that you are generally expected to not retrieve more than you’ve input in the same month, no?

No. It's basically one download of all your data in 1 month [1].

For example, if you store 100 TB with Wasabi and download (egress) 100 TB or less within a monthly billing cycle, then your storage use case is a good fit for our policy. If your monthly downloads exceed 100 TB, then your use case is not a good fit.

In my experience it's an excellent fit for backups if you run disaster recovery tests quarterly on each set and have enough sets to run on a rotating, monthly schedule. You're only downloading about 25% per month at that point.

1. https://wasabi.com/paygo-pricing-faq/#free-egress-policy