It tends to run a little more when you're using hosting in a country that doesn't respect US copyright (and similarly for most EU) along with keeping your information private to begin with. When I had looked into it, it's been roughly 2x what a typical western dedicated server provider might charge.
This doesn't count the issues with a site that is very popular, from bandwidth to even simple database search overhead. If I were to guess, it's that RarBG probably spent in excess of $10k/month, which isn't much if you're a startup with a runway of VC capital or a revenue stream, it's a lot more if you're in a smaller country or don't have an excess of revenue.
