So guys I'm not sure if you googled this before, but I think that everyone must know this before playing Path of Exile as there is no gold and only orbs.
Vendor Recipes - Path of Exile Wiki
This recipes makes you get orbs, and each orb is considered currency. I love the traditional currency wich is 1 exalted = 6 GCP so I use this table to see wich orb is better or how much to offer for items etc..
Path of Exile Currency Exchange Rates
I hope this helps you guys