[realsdx]

If it's truly p2p, some relay would be there in case the client cannot be reached through NAT. Not sure how they would bear the cost of the bandwidth for unlimited transfers in that case

[wongarsu]

Traffic is pretty cheap outside the big clouds. For example Hetzner charges $1/TB on a 10Gbit connection

[throwawayffffas]

Their 1Gbit connections are unmetered.