Everything is boosted via the paladin....
main->a-b-c-d
First set: 4 paladins
Second set: 4 Priests
Collect free warriors on main, a, b, c
Third set: 4 warlocks
Fourth set: 4 mages
Collect free rogues on main, a, b, c
Fifth set: 4 hunter
sixth set: 4 shaman
Collect free druid on main, hunter on a, mage on b, warrior on c
Transfer hunter on a to main
Transfer mage on b to main
Transfer warrior on c to d
Create rogue on d and power level with a fresh toon on c, use anything on main, a and b to do it.

That's 3 transfers and a duplicate toon on one account. But that is doing the 0 to 60 grind 7 times..... From estimates, that'd be about 140 hours of playing or about 1.5 hours per day for 90 days. Considering how I have 3 weeks of vacation, I'm thinking this is realistic.
Cost would be 20 * 4 + 30 * 4 + 40 * 4 + 25 * 3 = $435 to do the transfers + new account costs and expansions.