Tool Ammortization Cost

Hi Experts,

I have a problem. I have developed a component cost of which is Re 1/-. Tool cost Rs 5000/-. Ammortization cost Re 1/- per Pc. After suppling 5000 pc price of this material will come down from Rs 2/- to Re 1/-.

How I map the same in system. So that when we receive 5000 nos, system automatically reduce the price of this mateial to Re 1/-.

Full points for helping answers.

GR