He also can't play without the latest version. The guy has a point, with every new day it becomes more apparent that very little thought has gone into this game or it's release.
The first couple updates released after launch were a bit sizable (~2GB) but no way do even all of the patches released in the 5+ weeks since launch make up even half of his monthly bandwidth quota.
It's also interesting that the game has eaten his quota for 3 consecutive months even though it's only been out since September 13th, and the preorder beta began only two weeks earlier. So I'd bet it's his kids that've used the bandwidth, not RO2.
I do admit though that updates in general have always been rather messed up in Steam for many non-Valve/Source-based games. I remember a series of multiplayer balancing updates being released for Company of Heroes. For people with the DVD version, this meant downloading patches around 3
megabytes in size, while those who bought the Steam version always had to
redownload the entire game (6-8GB) with every single patch.
As far as I know, this isn't exactly the game developers fault but more of an imcompatibility issue between the Steam updating system and the way the game's file/package system works, i.e. Steam cannot incrementally update a specific file and therefore the user has to redownload the entire (huge) file.
So if you have a connection with limited bandwidth I would suggest either switching the service provider or simply not buying games that require Steam.