PcgsInvUi/ViewModels/MainWindowViewModel.cs

@@ -116,10 +116,14 @@ public class MainWindowViewModel : ViewModelBase {
                 // TODO Clear the text boxes.
             });
         
-        // Change TotalValue anytime SelectedCoin.TotalPrice changes.
+        // Update TotalValue anytime a coin's quantity changes.
-        // TODO: fix this. Should update when a coin within the collection is changed.
+        // Possible null reference is currently ignored - SelectedCoin will never be null.
-        // Possible null deref - how do you remove this?
         this.WhenAnyValue(x => x.SelectedCoin.TotalPrice)
             .Subscribe(_ => TotalValue = ConnectedCoinDatabase.Collection.Sum(x => x.TotalPrice));
+
+        // Update TotalValue anytime a coin is added or removed.
+        ConnectedCoinDatabase.Collection.CollectionChanged += (sender, args) => {
+            TotalValue = ConnectedCoinDatabase.Collection.Sum(x => x.TotalPrice);
+        };
     }
 }

PcgsInvUi/Views/MainWindow.axaml

@@ -48,7 +48,7 @@
                                         Binding="{Binding Designation}"
                                         IsReadOnly="True" />
                     <DataGridTextColumn Header="Est. Price" Width="*"
-                                        Binding="{Binding PriceGuideValue}"
+                                        Binding="{Binding PriceGuideValue, StringFormat='${0:0.00}'}"
                                         IsReadOnly="True" />
                     <DataGridTextColumn Header="PCGS #" Width="*"
                                         Binding="{Binding PCGSNo}"