Hello Peter,
If your mirror is added, with 1TB on a 1Gbps port, you will easily exceed your quota. Typically mirror hosts operate unmetered transit services, and the bandwidth they can allocate to the mirror from the transit is the value included here.
Although your offer is greatly appreciated by the community, I would reconsider your offer. If you do decide to stay (and Anssi and/or Fabian accept your mirror), you will be asked for the connectivity speed.
Thanks,
Christopher H.
Sent from my iPhone