How about using something like Websockets to reduce outbound cost? It'll have anyone on the page viewing the media also host the media for their fellow web surfers. If I recall, there is a socket-based bittorrent library floating around somewhere - https://github.com/webtorrent might be a good start. :)

Serve the static web-page files from a decent host. Seed the 5tb of content from the cheap host.