https://trotuar-moskow.ru/t/v1276/images/js/addons_site.js

1$(function(){
2	$('.shop2-product-amount button').on('click', function(){
3		let $this = $(this),
4			prodAmountValue = +$this.siblings('input').val(),
5			prodPrice = +$this.parents('.shop2-product-item, .shop2-product').data('thisprice'),
6			prodPriceValue = $this.parents('.shop2-product-item, .shop2-product').find('.price-current strong'),
7			totalPrice = prodAmountValue * prodPrice;
8			
9		prodPriceValue.text(totalPrice.toLocaleString('ru-RU'))
10	})
11	
12	$('.shop2-product-amount input').on('change keyup', function(){
13		let $this = $(this),
14			prodAmountValue = +$this.val(),
15			prodPrice = +$this.parents('.shop2-product-item, .shop2-product').data('thisprice'),
16			prodPriceValue = $this.parents('.shop2-product-item, .shop2-product').find('.price-current strong'),
17			totalPrice = prodAmountValue * prodPrice;
18			
19		prodPriceValue.text(totalPrice.toLocaleString('ru-RU'))
20	})
21});