My first Excel script

Private Sub Worksheet_Activate()

End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim Oldvalue As String
    Dim Newvalue As String

    'On Error GoTo Exitsub
    If Target.Column = "5" Then

        If Target.SpecialCells(xlCellTypeAllValidation) Is Nothing Then
            GoTo Exitsub
        Else: If Target.Value = "" Then GoTo Exitsub Else
            Application.EnableEvents = False
            Newvalue = Target.Value
            Application.Undo
            Oldvalue = Target.Value
            If Oldvalue = "" Then
                Target.Value = Newvalue
            Else
                Target.Value = Oldvalue & ", " & Newvalue
        End If

        MsgBox (Target.Value)
        Debug.Print Target.Value

        'Suzdavane na spisuk s ceni
        Dim dict As Scripting.Dictionary
        Dim total

        Set dict = New Scripting.Dictionary
        total = 0

        'Populvane na spisuk s ceni
        dict.Add Key:="Чипс", Item:=2.8
        dict.Add Key:="Хляб", Item:=1.4
        dict.Add Key:="Шоколад", Item:=2.4
        dict.Add Key:="Безалкохолни напитки", Item:=1.8

        Dim selectedItems() As String
        selectedItems = Split(Target.Value, ",")

        For Each element In selectedItems
            If dict.Exists(Trim(element)) Then
                total = total + dict.Item(Trim(element))
            End If

        Next element

        Dim PRODUCT_PRICE_COL_NAME
        PRODUCT_PRICE_COL_NAME = "F"

        Dim prodPriceCol
        prodPriceCol = PRODUCT_PRICE_COL_NAME + CStr(Target.Row)
        MsgBox (prodPriceCol)

        Range(prodPriceCol).Value = total

        MsgBox (total)

    End If
End If

Application.EnableEvents = True
Exitsub:
Application.EnableEvents = True
End Sub