Suggestion - Movie Rental/Purchase

I would like to make a suggestion.  I would prefer to rent movies I have never seen before purchasing, but I hate to spend the rental money AND the cost of the movie.  It would be great if when I rented a movie, I immediately had the option to purchase it at reduced cost.  If I rent a movie for $6, it would be great if I got an email or message asking if I would like purchase the movie for say, $14, instead of the full $20.  Just a thought.  Thanks.