<div class="quantity_select">
<select name="cart[d3207bfbf377b2c6a2d5f0f397ecef61][qty]" title="Qty" class="qty">
        <option value="500" data-qty="500" data-price="0.27" selected="">
            500&nbsp;envelopes&nbsp;$135.00            </option>
        <option value="1000" data-qty="1000" data-price="0.18">
            1000&nbsp;envelopes&nbsp;$180.00            </option>
        <option value="2000" data-qty="2000" data-price="0.15">
            2000&nbsp;envelopes&nbsp;$300.00            </option>
        <option value="5000" data-qty="5000" data-price="0.15">
            5000&nbsp;envelopes&nbsp;$750.00            </option>
</select>
</div>

$('.qty').each(function(i, obj) {
    if ( !$('option:selected',this).index() <= 0) {
            $('.actions').find('input[name="update_cart"]').click();
        }
});