I'm going to disagree with some previous posters.
On UoP's website they state that their average RC score is a 22. Of course, this means lower scores than 22 get in, but a 17 is probably pushing it. RC is seen as one of the most important scores.
If your GPA is low like you've said, and your RC is a 17, I think your chances of a UoP interview are slim. If you're comfortable with what will most likely be a waste of $200, go for it. I'd spend it on another school though.