You should be able to get away with only needing 350 tokens - provided you don't want to keep the outfit.

Save up 350 tokens, then buy all 3 pieces of the Brewfest Garb.
Go to Dalaran, put it all on, get smashed. Disturbing the Peace is done.
Go back to Brewfest and return the 3 items to the vendor.
Take 200 tokens and join the Brew of the Month Club.

Done.