If it's a simple sum you're after, you can simply run an update code on the keyup and change events of all input elements:
$("input").change(function(){update();}).keyup(function(){update();});
To update them, first you need to check and see which one of the two radio buttons are checked and get its value:
function update(){
var p = 0;
for(var i = 0; i < $(".calc").val(); i++)
{
if($($(".calc")[i]).prop("checked") == true)
{
p += parseInt($($(".calc")[i]).val());
}
}
After that, simply parse the values of the textboxes to integers and add them to the value of the radio button. I created a custom function to do this, because if the boxes are empty, parsing them returns NaN:
p = parseInt(p);
p += parseInt(val2($("#ancho")));
p += parseInt(val2($("#alto")));
p += parseInt(val2($("#cantidad")));
p = parseInt(p);
$("#price").html(p);
}
function val2(elm){
if(isNaN(parseInt($(elm).val())))
return 0;
else
return parseInt($(elm).val());
}