A cynic would say the same about the iphone. I think there's a good fit here - the same kind of people buy both, so there's lots of opportunity for cross-promotion.
But not $3 billion+ worth of opportunity. If all they wanted was cross-promotion there are plenty of ways to do that without buying the company outright. If Apple wanted to get into the fashionable accessories market they have enough brand clout to do so on their own, without having to buy an existing player.