In order to obtain the valuation of the stock stored we will go to:

 Inf. And Statistics → Products and Stock → Products in Stock

We will open a window where we will have to choose the family, brand and store of the article that we want to know its valuation.
And we will click on the button "Get report".

Once we have clicked on the button "Get report", we will get down articles, quantity, family etc ... and in the last column we will see the value of stock.