So I have an unhinged foil Island on my wishlist and according to that they're selling for $7.84. Thinking that's a great price (esp since they're selling on eBay for $50) I click on the green "Buy this card now" link and that doesn't pull up foil unhinged Islands - that pulls up Islands from every expansion ever and doesn't provide a way to filter that list. It seems like that'd be a useful feature.

Yep, true! A button to restrict the listing to exact matches is planned there, as well as another button that filters only the sellers that are shipping the card to your country too.