var prices = [{id:56233, min:1, max:200000, price:'$524.99'}];

$(document).ready(function(){
  $('input.addToCart').keyup(function(){
    qty = $(this).val();
    
    $('tr.price_row').each(function(){
      $(this).removeClass('highlight');
    });

    $.each(prices, function(){
      if(this.min <= qty && qty <= this.max) {
        $('#current_price').html(this.price);
        $('#price_' + this.id).addClass('highlight');
      }
    });
  });
});