Posted: 01/05/2013 at 11:21
The performance benefit depends how fast and how far and how regularly you're running to start with. For example, if you jog 2 miles twice per week, you aren't going to need expensive kit. However, if you train twice a day, with one of those runs at a high percentage of your maximum, then kit that increases comfort and aids recovery like compression tights, performance shoes etc.. will probably be more important/necessary/beneficial for you.
Unfortunately, it is a bit of a cycle - when I was a student training a lot more and faster, I would probably have benefitted from better kit. Unfortunately I couldn't afford it until I was working, and thus have no time or energy to train at the same intensity!!