$(function(){
  $('.bid_btns_add button').on('click',function(){
    var current_value = parseInt($('#bid_price').attr('value'));
    var add_value = parseInt($(this).val());
    var total_value = current_value + add_value;

    var output_value = total_value.replace(/(\d)(?=(\d\d\d)+(?!\d))/g, "$1,"); //error               
    var output_value = total_value.toLocaleString(); //error

    $('#bid_price').attr('value', output_value);
  });
  $('.bid_btn_clear').on('click',function(){
    $('#bid_price').attr('value',0);
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.0/jquery.min.js"></script>

<div class="bid_btns_add">
  <button type="button" class="" value="1000">1000</button>
  <button type="button" class="" value="5000">5000</button>
  <button type="button" class="" value="10000">10000</button>
</div>

<input id="bid_price" type="number" class="input_price" value="0"></input> 
<button type="button" class="bid_btn_clear">x</button>