How important is amount of Video RAM

hi all

i know that amount of vRAM on a graphics card is not that important untill you start playing on extremly high resolutions.

And i'm playing always on 1024x768, because i see no reason to go higher.
Games i play are only mmorpg, EverQuest2 in particular.
I need to buy a new graphics card now, since my last radeon x1800XT broken down.
I just can't make a decision, was looking at 8800GTS, but i think it's too expensive to pay so much for a 640MB version, and 320MB version could not cope with huge amount of details in game.

EverQuest2 is very heavy on graphics... my old X1800XT was best to run at balanced settings, going higher on quality would often drop frame rates very low.

I was even considering getting 1950XT, because it's cheaper than 8800GTS 320MB and has more vRAM. I know GTS 320MB would win in most of a First Person Shooter games, but i absolutely don't care about all the shooter games, like F.E.A.R. or Quake or whatever... All i play is mmorpg.

Would someone tell me, how important is the amount of video memory in a mmorpg games that are heavy on details?