Yes... I'll explain how when I get back from lunch. =)
**Back
Basically, you have to use a neutral AH. BB will be your best bet for your level so get both characters there at the AH. What you do, if you want to transfer say, 300 gold, take a crappy grey item, with your drenai and post it up for 300 gold. Then you log in your mage, and buy said crappy grey item for 300gold. Now, the exchange rate is higher on neutral AH's, but that's the way you do it.
For items, its much more risky, and much safer with 2 separate accounts. Basically, you wait until there's like nobody on. VERY early morning is usually best. Then you post your Epic Lewts up on the neutral Ah for a few copper. Immediately log out and purchase it on your low lvl. If you have 2 separate accounts then you can just submit the auction with one and search for and by the item on teh other. Otherwise you have approx. 30 of downtime between logging out and back in. So there is a 30 second window of opportunity. I do know that there are some people who will sit and watch these AH's during slow server times because they know this happens. Be wary and aware of the risks you run. Have fun! Voila.
Note** If you are on a PvP server and only have 1 account, then you are screwed unless you have a good friend you trust who will help you do the above on their account. PvE servers allow you to have both Horde and Ally characters. Anyway, there you go.