$(document).ready(function(){
    var quantitiesFields = $("input[name='quantities[]']");

    function calculateBasketPrice() {
        var basketPrice = 0.00;

        quantitiesFields.each(function() {
            var quantity = parseInt($(this).val());
            if (quantity) {
                var price = parseFloat($(this).next().val());
                if (price) {
                    basketPrice += quantity * price;
                }
            }
        });
        basketPrice = basketPrice.toFixed(2);

        $("span#basketPrice").html(basketPrice);
    }
    quantitiesFields.change(function() {
        calculateBasketPrice();
    });
    quantitiesFields.keyup(function() {
        calculateBasketPrice();
    });
    calculateBasketPrice();
});