http://auctioneeraddon.com/
Actually, to add to the point about vendor items being sold on AH, there's the Darkmoon Faire going on right now, and two of the vendors sell items ranging between 16s-40s that sell on AH for 2g-50g. There are some gems like Star of Elune and herbs like Black Lotus. I have the feeling that the prices will fall over the next week because of the higher supply, but they will go back up over the faire is gone. I mean if the price for a Star of Elune was previously 45g, it means it went up after the last faire.
Here's a list of items that are worth buying from the Darkmoon Faire:
- Star of Elune
- Noble Topaz
- Nightseye
- Talasite (only so-so)
- Dawnstone
- Living Ruby?
- Black Lotus
- Fel Lotus
- Mote of Mana
- Mote of Life
- Mote of Fire
- Mote of Water
- Mote of Wind
- Mote of Earth (only so-so)