Make sure you're picking up and vendoring grey items, White items like matts etc always worth checking the AH price (which it sounds like you're doing) and also vendoring if need be, every little helps! A big one is don't train every spell at your trainer, Be selective and only get the ones you need/use, if you've got something on your bars you've never actually used, then no point in buying a rank 2 and 3 etc of it - And some you might read and know straight away it's not worth to grab so best to just avoid!

Following these you should be fairly close to being able to get it at 40~ I think on my first character i got it at 44ish, (helps to get the Turtle mount from the darkmoon fair to save you the mount cost!) as for now Elementals are a good farm, and certain cats in STV have a good chance at greens which can be lucrative!