I'am aware that alot of people may already be aware of this trick, but i searched and did not see it, so I figured I'd post this anyway.
Basically what you do make mithril casings and sell em on the AH, I sell mine for about 15g BO, and 10g Bid, and since bars mostly avg around 1g 50s (its like this on my server, and wow head says same price too), its only costing you 4g 50s to buy three of them to make one casing, so you profit about 5.5g - 10.5g each casing. If you feel you can sell it for higher, go right ahead, and let me know how it goes,
If you try this on your server please post your server and faction so I can list which servers this is currently working on.
Servers this is currently working on:
Korgath - Horde/Neutral
Servers this is not working on atm:
What do I need to do this?
Engineering (215)
3x Bars of Mithril
Why is someone going to buy my mithril casing for such a high price?
Mithril casing is used for Chasing A-Me 01 - Quest - World of Warcraft in ungoro crater, and since this is available to both sides you can put it on neutral AH, or your faction AH. Also if you notice that there is no competition on the AH, send a few to an alt and post them on the auction house for about 10g + what your price is, people will think that they are getting a good deal buying yours that way
What do I do if I can't afford to buy a stack of mithril?
There are many different routes you can take to mine mithril your self, but i prefer the one below because if your're mining is high enough you can mine mithril, dark iron, small thorium, and rich thorium. I fould about 4 arcane crystals which can sell for a lot(15g on my server) while doing this, and used the thorium to level my engineering to 300
here's a good link for other routes if you find the above route too crowded or high level
WoW Mining Guide 1-375 | Free WoW Guides
Why don't most engineers already do this?
Simple, most people only make these to level their engineering, because you need about 70 bars of mithril to level it to 245 as shown below. Most people are usually only concerned about getting to 300 for out land, they usually overlook this nice way to make some easy g.
This has been working for me on my server for awhile, and with some luck it might work for you.