I didn't start looting until the mid 50s so I actually had to take gold from an existing character for their level 40 mounts. I had 1000-1200g on each of them when they hit 70 and another 1500 on my auction alt from sending all their greens and such. I also have a couple bank characters full of motes, enchanting mats, mined materials and quest items(for the next group). I worked on no professions with the exception of mining on one character, which definitely paid for itself and the little time it slowed me.

This is based on boosting to 45 with a high level character grinding instances and 46-70 questing. I bought nothing from the auction hall except for quest items.

The short story is if you loot you should have your mount money at 40, you definitely have your money for your epic and flyer from questing.