All depends on what kind of content are you serving to your visitors. For a tube site, you might like to try an upgrade first, since that much bandwidth from a CDN could be a bit expensive. If you have a lot of photos, maybe you could consider getting a CDN. I might be wrong, though.
This is probably the cheapest CDN in adult I have seen:
https://www.m3server.com/services/cdn/
I have no experience with them. Would be glad if anyone could share theirs.