If you are horde go to Hinterlands, do not stop, do not pass go, don't worry about the $200.

I found that in the Hinterlands, with no booster, I can do 170-200k an hour (per toon) depending on the class. IN the BRD Lycum (with a never ending stream of mobs) boosting with my 70 Pally in OK gear I could hit maybe 125k.

After Hinterlands Ungoro is about the same and the cauldron quests in WPL are nuts. I keep saving the AD turnins but keep hitting 60 before I get there.

In my gear level I have found questing to be MUCH faster 45-60 then boosting. It also give you a chance to get used to your toons. I had never really played shaman before RAF and quested 40-60 and learned a lot doing it. This may or may not matter for you.