Thank you. I have managed to reproduce the issue. When trying to purchase the same item in your store, I've been added £2.50 for Shipping and handling on PayPal side.
Most probably, this has happened because of your PayPal account settings. Please, refer to this post for details:
According to the order details in your store backend, "This order is in the "Queued" status, because the order total and the amount actually paid do not match. Please check this order in your PayPal Admin Area for possible issues."
Please also refer to the following article in our knowledge base: