I think part of the reason is people look at Linode/Vultr/DO and presume that 1/2TB for $5 is the market price (and then quote HE.Net/Cogent/Hibernia offering 10G to certain colos at $2-5kpm as backing proof), or dedicated servers with 10TB for $50pm etc... Linode/Vultr/DO mainly work off an average usage of 1%-2%, although at least they dont stop you deploying more boxes as you reach the limit, you can get clever and one would presume they dont invoke some TOS clause. I imagine GCP, AWS, and Azure bandwidth cost is closer to the truth at running a network that is resilent and can scale beyond 100G, the transit or costs of fiber is probably only a tiny fraction when pushing beyond 100G per region, vs your low end VPS provider, let's not forget the epic fail of Linode DDOS handling. I do agree though in comparison it sounds expensive.