Prices not showing on variants in Woocommerce

Hi,

I have products that have variants in size in my woocommerece shop. The problem is when a product has variants the price will not appear when the choice of variant is made. If i give you the link could you check to see if there is a js issue or something and see which plugin could be the problem?

the link is : http://ynfa.net/product/ynfa-premium-polo-shirt-epl-football/

you will need to do a quick login to access the page.

Many thanks