With a fiber connection, 5-20 terabytes/month is nothing. I could probably ramp it up, but I'm only looking for 1080p content. The only thing that keeps me sub-petabyte is that my budget doesn't allow for a NAS with enough bays (and 20tb disks going up to $500ish here lately surely hasn't helped).
Really, just start downloading every new release and you wouldn't even have to dip into the back catalog much.
Really, just start downloading every new release and you wouldn't even have to dip into the back catalog much.