I would put the files on a S3-like service (scaleway, backblaze...) and setup a small VPS to serve the files.

By using Scaleway you would pay ~12€/m for 1TB of storage and ~7€/m for the smallest instance (can go even cheaper if you manage to get a stardust instance at ~1.5€/m). Also, Scaleway does not charge for egress (bandwidth) so it seems the perfect solution to your problem :)

Alternatively, you could enable the website feature[0] on the bucket to save you from setting up a web server, but then you would pay for the egress.

[0]: https://www.scaleway.com/en/docs/storage/object/how-to/use-b...

Disclaimer: I'm just an happy customer