Unless it does something stupid, most of those settings should be graphics settings, meaning that the ram is uses (higher quality models, high res textures, etc.) should eat up more video card memory than computer memory. I highly doubt that a game would ever require 8GB to function properly.... Unless they fucked up and wrote some shitty code.
When you have bills and have to get your car fixed you don't have alot of money to build a new rig. Going from 1 to 2 gigs mad a huge difference in loading speed for tf2 and l4d2.
I just said it depends on how much you had. I know very well that a rig with 1 GB really does benefit from an extra GB of ram. I was kinda bitching about how there are all these pre-built systems that come with like 8GB ram and crap and are billed as gamer rigs when in all honesty, if a game requires 8GB of system ram (as in, non-dedicated video ram) then there's an issue somewhere, either in the memory management in genral, or in what the programmers are loading. I don't think most games could use up 8GB of ram if they tried. But if you were using a dedicated server or something, you could eat up 8GB in no time flat. Even the old Mu Online server I had (which was designed to run in a distributed system, with differnet server programs on different computers) could eat up a couple GB without much trouble. I think the game server by itself ate up a minimum of 800MB, and the 2 database servers ate up about 250 MB each. (well, 2 regular database servers anyway, there was another dedicated one for PVP stuff). And that game wasn't really a high requirement game as far as servers go.