uh, stupid question but where can i buy these addons? (https://supabase.com/pricing). Can't find it anywhere.

You can request any of the addons using the support page for now. We have rolled out self-service for some accounts already but this is still ongoing. https://app.supabase.io/support/new

On the Supabase dashboard, you can select Settings / Billing & Usage / Change Subscription / Edit Plan and this will allow you to upgrade and downgrade your project at any time.