Replying to The best quality sound

I have a pretty decent setup with my camera (Sony Alpha a58) with a standard starter lens (18-55mm). Which can do for now since i currently have no money. A Fly cam nano and a Røde videomic. in the past couple months i have been recording a lot of skiing and getting some great shot but my mic picks up a bunch of wind. I have looked into buying a new windshield (currently just have the on that it comes with) like the "Rode Microphones WS6 Windscreen" which I have heard works pretty well for the price of $50-$60. Should I buy the windshield? Should I buy a new microphone? thoughts?