Question

I don’t understand why but .parent() is not working on dynamically created elements.

Here is fiddle displaying my problem. It calculates discount price on static element, not so much on created one.

$('.item-sizes .discount-percent').live('keydown', function () {
        var percentValue = $(this).val();
        var basePrice = $('.base-price', $(this).parent().parent()).val(); // Undefine on live elements, defined on static

        if (basePrice) {
            discountValue = basePrice - ((percentValue / 100) * basePrice);
            $('.discount-price', $(this).parent().parent()).val(discountValue);
        }
});

Answer 1

You have the base-price class on the wrong element:

<input type="text" name="text[]" placeholder="foo" class="span3 base-price"/>

which explains the NaN response

here it is fixed:

http://jsfiddle.net/znvHa/5/