The cost of a free player (or ANY player for that matter) has little to do with bandwidth. I guess you don't know anything about overhead, labor rates, cost of goods, etc. In a game like this...the cost is basically already calculated and is not spread across the player base. It's a set standard that is probably good for about a few million more players until they have to dump more money into servers, etc. Trying to spread cost across each player makes it look like the cost decreases per player. However, were talking about real financial formulas here and I guarantee 98% of the people on the forums have no idea what I'm talking about.
I really wish people would stick to things they actually know about instead of coming to the forums and trying to sound smart. Really. Stop it..
I am comparing what the cost difference would be between "Free Player Bob Plays SWToR" and "Free Player Bob Plays Something Else" if I were hosting the free players myself. I am doing this in response to the people saying "freeloaders should pay or get out" or "free players are a financial burden on Bioware." I'm not trying to sound smart, and if it looks like I am, I apologize. (I'd settle for 'vaguely credible.') I'm trying to bring some data into this, specifically that the price of adding players isn't nearly as much as people seem to think it is.
The truth is that additional free players cost next to nothing. Or, as you say, until a certain point, really nothing at all. (And after that not very much.) It's napkin math and not a rigorous fiscal analysis; the advantage is that anybody who doubts the price of hosting can follow the links and do the math themselves.
I know about overhead and labor costs, thank you, and that spreading the cost per player isn't precisely accurate. Whether a free player comes or goes has little bearing on the money spent on any of it - except hosting.