Thats a horrible limitation, I probably do that in a few days on average and on a good day can do more than that in a single day. As far as mmorpg terms go they usually use relatively small packets and do not transfer much so you should probably be safe. I honestly have never cared about up and down rates, but I would guess that at most you would be talking about 5 per month max if you play some hardcore sod. It should be about the same amount of packet transfer as an fps. I would be worried about the initial updates though because those are probably 5gigs or more for the eq updates.
In all honesty apps like teamspeak and mirc are probably worse on bandwidth than sod.
Yeah, but seriously limiting your bandwidth at such a low number is horrible. I guess I consider it low because I have an larger than normal bandwidth requirement.