Only reason to get 5 more is if you plan on 10 boxing at some point Really to me just seems like a waste of $$ in the name of laziness. Which I can sympathize with I'm lazy as hell and after the RAF experience 1-60 does seem a chore. In actuality you really only save a couple of days if you're boosting toons.

Cataclysm is still a ways off- and day 1 of it you'll be exchanging out gear. I'm in a similar situation 4 druids, 1 pally, 1 rogue at 80 and would like to get more 80's for variety. I'm just going to boost 4 at a time and once they hit around 70 continue boosting with my 80 geared team.