Aliexpress display price per unit with shipping (greasemonkey)

aliex_price_unit_ship.js

// ==UserScript==
// @name         Aliexpress Price per item with shipping
// @namespace    http://tampermonkey.net/
// @version      2.0
// @description  try to take over the world!
// @author       vik
// @match        https://www.aliexpress.com/*
// @grant        none
// @require      http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js
// ==/UserScript==


'use strict';

$(document).ready(function() {
    $('head').append("<style>.tpz { color:#0b0; font-size: 14px; font-weight: 700;}</style>");

    function checkPrices() {
        $('.list-item').each(function (idx, item) {
            // ignore done
            if ($(item).hasClass('tpz-done')) { return; }

            var val = $(item).find('span.price-current').text();
            var qty = $(item).find('span.price-unit').text();
            var ship = $(item).find('span.shipping-value').text();

            if (val.indexOf('-') > 0) {
                val = val.split('-')[0];
            }

            val = val.replace(/[^0-9,]/g, '').replace(',', '.');
            qty = qty.replace(/[^0-9,]/g, '').replace(',', '.');
            ship = ship.replace(/[^0-9,]/g, '').replace(',', '.');

            val = parseFloat(val);
            qty = parseFloat(qty);
            ship = parseFloat(ship);
            val = isNaN(val) ? 0 : val;
            qty = isNaN(qty) ? 1 : qty;
            ship = isNaN(ship) ? 0 : ship;

            var new_e = ((val + ship) / qty);

            $(item).find('div.item-price-wrap').after('<b class="tpz">Per unit: ' + new_e.toFixed(3) + '</b>');
            $(item).addClass('tpz-done');
            //console.log('VAL:', val);
            //console.log('QTY:', qty);
            //console.log('SHIP:', ship);
        });
    }

    checkPrices();
    setInterval(checkPrices, 2000);
});