//when select variation in single product page
var is_single= <?php echo is_product()? '1':'0'?>;
forms = $( ".variations_form" );
if(is_single)
forms.on("woocommerce_update_variation_values",function(e,dt){
//this timer is important!
setTimeout(function(){
var price=$(".woocommerce-variation-price .price .woocommerce-Price-amount").html();
console.log("fire variation:",price);
if(price) $(".price-wrapper .product-page-price").html("<span class=\"woocommerce-Price-amount amount\">"+price+"</span>");
},200);
});