Extended class functions

Lets say i had a simple class that extends another class:

 class Item {
   private var name : String = "itemName";
   private var price : int = 21;
   private var weight: int = 1;
 
   function _get(what:String){
         if(what=="price")return price;
       if(what=="weight")return weight;
   }
 }

 class Weapon extends Item {
   private var damage : int = 10;
   private var speed : int = 5;
 
   function _get(what:String){
       if(what=="damage")return damage;
       if(what=="speed")return speed;
   }
 }

 function Start () {
   var wep = new Weapon();
   print(wep._get("damage"));//prints 10
   print(wep._get("price")); //prints 0 ???
 }

The problem is - i can't seem to get the base class variables - price or weight in this example. Maybe there is a special way of extending a function?

Any help would be appreciated.