To Kring, HokieJayBee, and David....
I'm kicking myself right now for not investigating the event more thoroughly. I should have looked up a strategy guide for the event, or even posted sooner, and all this would have been avoided. I originally wanted just the Elekk, and only after a couple of days had passed (and I had already gotten the Elekk on all toons on Demon Soul) did I start thinking about getting the achievement.
But, as has been pointed out, it's not necessary to drink each Brew of the Month to get the achievement, you just have to join. So, if I only get my toons enough tokens to join this year, I'll just wait for next year to see if my toons are high enough to warrant getting the other 350 tokens for the clothes, as well as killing Coren, thus getting the title at that time. Or, I could just hang on to the tokens that I get this year, wait til next year to get to 350, and follow the advice of buying the clothes, wearing them in Dalaran, returning them, and THEN buying the membership. I dunno, I'll make up my mind at the end of the week.
Wish me luck on getting some of my toons enough tokens this year that they won't have to repeat the hell of running kegs ad nauseum next year!