calculateTotal = function(){
  var total = 0.0;
  $(".subtotal").each(function(){
    total += parseFloat($(this).text());
  });  
  $("#grand-total").text(total.toFixed(2));
  $("#grand-total-input").val("R" + total.toFixed(2));
}
packageItemChange = function(){
  calculateSub($(this));
  calculateTotal();
}

calculateSub = function(item) {
  var selected = item.children("option:selected");
  var amount = selected.attr("cost"); 
  var selector = item.attr("id").replace("select-", "#subtotal-");
  $(selector).text(amount);  
}

$(document).ready(function(){		
  $(".package-item").each(function(){
    calculateSub($(this));
  });  
  $(".package-item").change(packageItemChange);
  calculateTotal();
});