Not sure about Horde much, but when I played an Alliance rogue, there was a vendor bought dagger at lvl 11. So you still have a lvl to go for it.
But I agree, check out the Auction House for gear.
Edit: It's easy to get to the blimp at lower levels for the Undead. Brill is like a 2 minute walk from the Undercity and the blimp tower. There aren't many mobs along the road and most are under level 10 or so.