You could do it with only 2 new throwaway accounts (currently $5 for vanilla/bc and $5 for wrath) but it would require leveling lots of throwaway toons (just to use them for level granting) and lots of paid character transfers. It's all about how much money you want to spend. I believe it was the second poster that suggested linking 2 new accounts to one account, then use a fourth account to do the boosting, level 5 separate trios to 80, then delete the toons on acct A, wait for pandaria, create 5 new monks, and grant levels like mad, then do 4 paid character transfers ($100) to your existing 4 accounts, and let the new RAF accts expire, or transfer the toons should you desire them.

Or just get all heirlooms and start from level 1.