Codeberg is not a 1-1 replacement for github/gitlab but for many people it is a better option.
I really wish there was a way to support with them a smaller amount then €24. I dont use codeberg myself but I really want to support them.
You can, €24 is just for the membership
Wire transfer is €10
Stripe is €5
With PayPal you can send €0.01 if you want
Or Liberapay, as little as €0.01 per week
I send them a couple bucks a month via Liberapay. I'm on mobile and short on time, but you can customize the donation amount easily.