How to manage sales price and cost price of an item?


Is there any way to manage sales price and actual cost price of an item?? My problem is if i update an item quantity it provides me the total sales value for an item in stock asset account. Where i need the total value of actual cost in that account.
For example, my manufacturing cost for item A is 20$ and i sell it for 40$. So, if i produce 20 unit of item A, total cost is 20x20=400$ which is my stock asset. But in ERPNext it shows 20x40=800$ in my stock asset which is a problem for me because sometime i need to give discount or reduce the price to my customers.

Is there any solution???

Set your stock price as $20 (or what you want to show in your books as asset value). Then make a different price-list for selling price.

Thanks a lot.