Movie Rentals vs Purchase.

I was hoping to make a suggestion. What would be nice is if you rent a movie at the end you could buy it and get partial credit for the rental, maybe half? 

I am suggesting this because it is really a commitment to buy a movie and then not like it that much, but if you rent it you’ve already thrown money at it, so you feel like- maybe you should just wait until it comes out on streaming,  or cable, or even a DVD. I know the movie I want to rent is now in Redbox, so I assume it will come out on that eventually. I would like to buy it, but I am also afraid to waste money. I hope that makes sense. Thanks for your time.