I considered this software before I went for my stage two, but I couldn't afford it and thought it kind of defeated the point of doing the tests, so I went without it and I'm glad I did as I know I passed on my own skills and didn't have the material to prep before I went down. It's a bit like being given the paper to an exam before you sit it, the people marking it may think you are great but in reality you have only been doing what you needed to do to pass. I'd have been worried if I got this that I was going to struggle in college as there is no software you can buy to help you pass the exams once you get there.
However that is only my point of view, and I'm sure a lot of people will have differing opinions to this.