title: ObservableCollection adds an item and overrides the others
body: <p>I have this function:</p>
  
  <pre><code>ObservableCollection&lt;TankstellenItem&gt; completeList = new ObservableCollection&lt;TankstellenItem&gt;();
          for(var j = 0; j &lt; listItem.Count; j++)
          {
              foreach (FuelItem fItem in listItem.ToList()[j].Fuels)
              {
                  Debug.WriteLine("HERE AGAIN: " + fItem.Price);
                  TankstellenItem newItem = new TankstellenItem();
                  ObservableCollection&lt;FuelItem&gt; fuelList = new ObservableCollection&lt;FuelItem&gt;();
                  newItem = listItem.ToList()[j];
                  newItem.Fuels = null;
                  fuelList.Add(fItem);
                  newItem.Fuels = fuelList;
                  completeList.Add(newItem);
                  Debug.WriteLine("PRICES: " + completeList.ToList()[0].Fuels[0].Price);
              }
          }
          Debug.WriteLine("COMPLETELIST LENGTH: " + completeList.ToList()[0].Fuels[0].Price + " + " + completeList.ToList()[1].Fuels[0].Price);
  </code></pre>
  
  <p>and the outcome is:</p>
  
  <pre><code>LISTITEM LENGTH: 1
  HERE AGAIN: 1,699
  PRICES: 1,699
  HERE AGAIN: 1,529
  PRICES: 1,529
  COMPLETELIST LENGTH: 1,529 + 1,529
  </code></pre>
  
  <p>As you can seein the foreach the Prices are different. But after the for-method the output is only 1,529 in every item. I don't understand why this happens.</p>