The galvanizing process is a method of coating corrosive metals, such as steel and iron, with a non-corrosive metal. Zinc is melted and applied, usually via what’s known as a hot dip, to the metal, providing a coating of corrosion protection from one mil to just over four mils thick.
Corrosion prevention! Steel in it's unprotected state will rust, trying to get back to it's natural state. Corrosion of steel is an electrochemical reaction between your steel and the environment. Very expensive for you to repair once it has taken place.
This depends on the amount of metal you want to have galvanized, usually we charge by the Kg, starting from 1.5€ per Kg for small jobs bringing this price down as the amount increases.