The Auctioneer addon is an important tool in the World of Warcraft, but has no part in the UI that I am slowly piecing together. Why? I use Auctioneer to streamline the whole buying and selling process. But the addon is a memory hog.
I want to spend as little time as necessary posting the raw materials my toons collect or the random equipment that drops. Plus Auctioneer lets me earn some money the old fashioned way... buying low and selling high. I earned about 5 gold with literally about 2 minutes of work. Not bad since I only have a couple under 20 toons on this server.
The first step in my system is to create a character that just hangs out in a capital city. This is the only character with the Auctioneer addon loaded. His only purpose is to move items from the mailbox to the auction house, and then send money back out. My other characters send him stuff in the mail instead of posting the stuff in the auction house themselves. This reduces time spent travelling and keeps my main characters' bags tidier.
The next step is to scan the auction house often, but not more than once a day. The key is patience. You can't download the addon, run it a few times and expect the magic to happen instantly. You want at least a week's worth of data to get a clear picture of an items real value. The more times it scanned the auction house, the more confident you can be in Auctioneer's suggested price. I click the Scan button and find something else to do. In fact, it's running as I write this blog post.
After the scan completes, I can mouse over the item in my bag and a new little tooltip tells me what Auctioneer thinks is the items real value. Also, in includes info if the competition is above or below price. No more having to search the auction house manually to figure out how much my stack of light leather is worth. That's not fun for me. Some people may enjoy it. Thank you, but I'll take the easy route.
Next up is searching the auction house for items priced well below market value, so I can scoop it up and repost it. Flipping under priced items is easy money... assuming you're willing to take the occasional loss. My rule of thumb is to not risk any more than I'm willing to lose. Right now it's about 50 silver. That's my threshold. I won't buy an item to resell for more than 50 silver. As my toons' wealth grows that threshold will increase.
I can't stress how important patience is to making money with Auctioneer. You need to wait for data to collect. You also need to wait to post items at the right times. I've had to sit on a good item for a few weeks, because some yahoos were underselling it.