$25 is ok... $50 is way too much.
If they included a copy of the Bluray or movie download when released for sale, it might be worth it. But not for a rental. For a rental I would be willing to pay no more than the movie theater price, about $10 to $15.
I just realized they they are trying to make up revenue from the loss of at least 3 movie tickets (i.e. 2 adults and a child). So $25 to $35 wouldn't be that bad for a family. I do think that $50 would be too much, though.