To play backseat problem solver... You have free ingress? So start up a few $5 DO droplets and serve files from there. That gives you 1TB transfer per month.
I haven't tried this, but my understanding is that's per droplet. So when drop A is about exhausted, start B and switch over the traffic. Then shut down A. Then start C and shut down B, etc. Unlimited transfer? (Until your account gets banned, anyway.)
OVH has unmetered (i.e. effectively unlimited) bandwidth and is well-established - enough that they have their own gTLD, at least. I often recommend them for situations like these where 1TB/month/instance may not be enough.
DigitalOcean Droplet bandwidth is pro-rated, you don't get the full pool when you create the Droplet, you get it over the course of the Droplet running across 28 days.
You might be able to do this with the droplets like you said.
With DO Spaces, it’s a $5/Mo subscription to spaces. You get 250GB of storage and 1TB of transfer. Anything more costs 1c per GB transferred and 2c per GB stores. You can create as many buckets as you want.
That’s the real story here. Paying market rate for bandwidth is like buying soda from a restaurant. They’ll gouge you and make a profit but you’re thirsty and it’s too late to shop around.
I haven't tried this, but my understanding is that's per droplet. So when drop A is about exhausted, start B and switch over the traffic. Then shut down A. Then start C and shut down B, etc. Unlimited transfer? (Until your account gets banned, anyway.)