anyone done 3 box on rampants in outlands? was it do-able?

i tried with my 65 prot warrior/61 frost mage/61 resto shaman.. was doing fine with 3 elites.. til 4.. abit tough, esp with casters.. seems 3box is not enough for instancing..

5box would be quite taxing on my pocket.. lol.. could 4 box solve my problem of instancing? the most fun of the game is instancing and i really dont wanna miss that...