Why can't I have a wish list for Android apps on the Google Play store? Or for music, movies and books to buy there? If you're going to provide that much for sale, you need to provide a way for people to manage their shopping for later, like Amazon does.
I'm guessing the answer is something like "everything is cheap enough for you to buy right now", but lots of cheap things makes shopping expensive. Some people like to budget.
Mokalus of Borg
PS - And some people have no concept of budgeting.
PPS - I suppose they're easier to serve.