Internet data use

So I have a 41 day uptime on my Nokia and it reports 526 GB download over the period of uptime. I have multiple devices streaming and a son that games online so I don't see that as a surprise for our usage. You could contact the support for that solution and ask them what to expect for the expected bandwidth usage. I would guess they could provide a good estimate as they know the capabilities and demands the system has for the level of service you are using. 

I have not given the usage calculation by the Nokia gateway much thought given the terms of the account usage allowed. It seems to be an awesome deal given how well it works for us here.