RM83 A Spark Plug!

I recently bought a used Perdana V6 Year 2000. I want to change the spark plug, but to my horror, it costs RM83 each (meaning RM83 X 6). An authorised Proton service centre could not tell me how frequent should Perdana V6 spark plugs be changed, other than saying the plugs are made of titanium. A friend said the plugs can last between 5-10 years. Can a Perdana use the normal spark plug, other than titanium made?

Reply:
The plugs are a specialised product, and similar plugs are used in other cars. They last about five years or more, and when they fail, the whole module needs to be replaced. Sometimes one can get used units, but like all used parts one can never be sure of the lifetime remaining.