Gifting movies you own in iTunes/Apple TV story

I own a movie and it resides in my Apple TV library. I want to gift the movie to a friend by purchase through iTunes/Apple TV store. Because I own the film, I cannot see the price of the movie OR find the option to buy as a gift in the iTunes/Apple TV store.

1. How can I do this?
2. Why is this such a difficult thing to do?

Help!