It's expensive because people think they are getting something exclusive if they pay a lot for it. Which begs the question why do people go to starbucks at all? It can't be that they like coffee since from my one experiance of the place what they sell isn't even close to being properly made coffee.
What your buying at starbucks is "lifestyle" go there and you can fool yourself your living a groovy edgy urban lifelstyle. what you really are is a shallow wanker.
If you want coffee a strong shot of properly made espresso is all you need.
Caramel-cinnamon double creme frappecino? anyone who drinks that crap has the palate of a deprived three year old.