Yes you’re right Michael but for me the wishlist is an important feature for my customers so I didn’t want to hide it. So for non-logged users I have the button linked to the account/wishlist page but it returns a message “You must be logged in to use your favourites list. Please use the tab at the top right of the page to login or register a new account.” It’s more user friendly to explain the situation than just send them to a register page.
By the way, is adding the price to the wishlist still on your list of things to do?? I’ll buy you some beer if you do : )