My internet plan tops out at 2 Mb/s upload so that wouldn’t nearly fill such a public tunnel broker’s bandwidth, and I would be glad for even half that, but right now I seed 500 GB of reasonably popular movie packs and the long-term average upload is a few kilobits per second, not worth spinning up the 10W HDD motor for. Yes, I expect some overhead with tunneling but not three orders of magnitude, and I need at least 100 kb/s to get a good ratio on those movie packs.