Hi,
I'm pretty sure that transfers between your own Paypal account are free.
You 'link' your UK and USA bank accounts to your paypal account. When you withdraw funds from a linked bank account to Paypal - that's free to do. Then, you can transfer money via Paypal from/to your other 'linked' account, which I'm almost certain is free to do as well.
I think the fee's are for when you are sending money to someone else internationally.
Drop in a support message to paypal and see what they say.
The reason I'm under the impression above, is that I have my UK bank account 'linked' to my Paypal, and also two USA bank accounts linked as well.
Cheers, DtM! West London & Slough UK!