Using it as a worst case scenario, but yes it is.Let's not beat around the bush here - 9GB is a very big file.
What I'm kinda thinking is that maybe the primary network can be used for streaming, and the secondary network for downloading? Depends on whether both are shaped or whether the shaping is network-dependant.
(I definitely see your point as well though, you still have to pay for and provide the same amount of data)