This is a completely legal addon, so I'm not sure where it goes, so if its in the wrong place, please move it.
First off, I don't want rep or such at all for posting this, I gathered information from other sites and am putting it here. Don't bother telling me not to steal from other sites, I didn't really, I more gathered information and compiled it here.
http://www.geocities.com/childoftorment/390.zip
BottomFeeder, uploaded onto my friends free storage of sorts.
EDIT: Fixed link should work now.
You need auctioneer (90% sure) for it to work right.
http://auctioneeraddon.com/
BottomFeeder folder is just thrown right into the AddOns folder in WoW.
A list of commands can be obtained while using it by typing /btm
All commands listed are input '/btm <x>' and <x> is replaced with the command line and the variables it requires as input
Now here is what BottomFeeder does, simply put, scans the auction house, sees items that are below the average sell price (for AH, vendors, or even disenchant sales) from a certain point (the percentages and values that are the bench mark for buying out stuff are all changable, just use '/btm' to figure out how to do so.) Now then, just open the AH window, type '/btm begin' and it will slowly begin doing its thing. Very, very, valuable indeed. Buy a bunch of crap then sell it all back into the system.
One problem I'm running into, is it runs rather slowly, I think the numbers by default are set to be a bit conservative and only buy up really really really good deals, so you'll get an item every 15-30 minutes or so, though thats based on my over crowded server. I know it can be set to go faster, and put out higher profit based on speed vs. profit margins, but I'm having some trouble getting it working just right again, ever since I had to reinstall many a thing on my computer. Any intellectuals that want to play around with things and see what they can come up with to get it running optimally, be nice if you could post it('/btm dryrun' reallly helps you test your settings.)
I'm going to play around with this alot more, and if I get it working right again, I'll update this topic.
Update: Okay, got it working right
Lower your percentages and profit variables (remember, '/btm' to see the commands and their values) by somewhere around 50%. All the variables add up at that point and you really get things going fast. Its quite awesome. If you're really interested in good deals, I'd turn on the 'allowbidding' and set the profit margins high, chances are you'll get something good eventually. This is a very very diabolical way to make money, and guess what? AddOns aren't bannable at all, it uses WoWs macro commands. Expect this not to work come BC.