You only need to spend $15 to get 3 more accounts. You dont need to upgrade to MoP to make use of RaF, its only up to level 80 anyways right? Plus they each come with a free 30 days, just toss them out after then without renewing since its cheaper just to buy another for $5.

You will have to read the RaF thread, because I think the cheapest way is to just start 2 new accounts which were referred from 2 old accounts, then those 4 accounts together with a booster to level.

The $25 xfer cost is going to hurt though.