Level your auctioneer

This bit of advice is one of the few times I will say do as I say, not as I do.  As an experiment a few months back I rolled a Deathknight and started playing the transmog market on a low pop server.  Even though I am flipping 100’s of items every two days, I really began to appreciate having the deathcharger to speed up the run between the mailbox and the auction house.  And this is even in the Tauren quarter of Orgrimmar.  So I strongly suggest you level your auctioneer up to the point they can have a mount, which is currently level 20.