During an AQ40 fun-rep-run I had a discussion about which mobs drop the Red Qiraji Resonating Crystal.
Many people think only those mobs after the first Boss would drop it. I do not know why. Sh*tty sources I guess.
So among the properly informed folks many know of the trick witch the first 4 mobs. If someone might not know, here is what I mean.
After entering the instance you should see the following. A Sphinx Patrol which you can just kill off, once it comes near to you. Actually you SHOULD, because that guy can be a nuisance. The other thing is a group of 4 stationary Anubisath Sentinel.
Here is where the trick starts. Those mobs are linked so upon attacking one you will pull all four. For a lvl 80 average equipped Character that should be not that much of a problem. Now kill 2 or 3 of them, leave the instance and the living Sentinels will reset and respawn their dead friends. So this can be easily repeated until the Red Crystal drops. I tried this twice and it took me about 20 minutes each until they dropped it.
And now we get to the point where we earn money with this.
Go to a capital and type something like /2 Selling Red Qiraji Resonating Crystal. (I know it's "bop". Just whisper me for more info!)
People WILL whisper you and if someone is interested enough tell him: "Here's the offer: You will accompany me for about one hour. If you have the mount afterwards you pay me 4500 gold"
Here is where it gets risky. There is - of course - the possibility that the mount might not drop. In that case you could add "... if not I will give you 500 Gold. Either way It'll be win-win for you "
Now the two of you just enter AQ40 and repeat the trick mentioned above. I managed to get 9k Gold in 2 days with it.
Good Luck, everyone.