NOTE: I leeched this, thought the PoE forum needed some activity.

Hey guys, as an active member of the Path of Exile trading forum I though I could expand my horizons a little bit and today I decided to share a method to flip certain items in orded to basically duplicate your number of Orb of Alchemy. I know that many of you will already know this but I'm almost certain that some others will find this new.

There we go!

1- Ask in trade chat to exchange your Orbs of Alchemy with Orbs of Alteration at the rate of 1:10 (even 1:12 if you find someone up for the deal)
2- Once you've gotten AT LEAST 40 Alterations, go to the vendor and exchange all those orbs for Jeweller's Orbs.

So now, you should have 20 Jeweller's Orbs right?
3- Exchange those Jeweller's Orbs for Orbs of Fusing at the vendor.

You should have now 5 Orbs of Fusing.

4- Last step: Ask in trade chat to exchange your Orbs of Fusings with Orbs of Alchemy at the rate of 1:1 and there you have it! In a couple of minutes you've basically gained an Orb of Alchemy for free. Now, rinse and repeat!
Credits: Wisheez