[caetus]

<div id="basket">

<div>
<span>цена</span>
<input type="checked" data-check="basket">
</div>
<div>
<span>цена</span>
<input type="checked" data-check="basket">
</div>

<div>
<span>цена</span>
<input type="checked" data-check="basket">
</div>

</div>

(function () {


var basket = document.getElementById('basket');
var price  = 0;

basket.addEventListener('click', fn, false)

function fn (e) { 
var e = e.target || e.srcElement;

if(e.getAttribute('data-check') != 'basket') return;

var price_ = +e.parentNode.children[0].innerHTML;

if(e.checked == true) price += price_;

else if (e.checked == false) price -= price_;

document.getElementById('елемент где будем выводить цену').innerHTML = price;

}

}());