Hello there! I found this place when looking for the updated levelling guides for 2.3 and, having found some, thought it would be rude not to say thanks and offer something back, so here goes
For this little tip, you'll need the auctioneer addon, which works perfectly in 2.3, very lovely!
Link to Auctioneer
Now, when you open up the auction house, you'll notice it looks a bit different. The 'scan' button will be your friend for the next 5 days
What you want to do is, on the realm of your choice, for 5 days perform a scan on the entire AH, during a peak time. This will collect a database of all the listings and their prices for you.
Now, when you have a decent database, click on the 'Search Auctions' tab.
Here, you can scan the auctions for items that would yield a profit of your choosing! For example: You can look for auctions that would give you a 1G profit, then items listed under your database's usual price will come up.
You simply need to buy them, relist them, then collect your earnings! ^_^
Apologies if this has been posted before, I know it's not exactly original. However, I thought, if someone wanted a money making scheme without wanting/being able to download a guide, this could come in handy.
Once again, thanks for all the great work on the guides!