S you have 1400 right? I saw it in your proflile pge. You can do anything you want with it really. Depends on you.. Personally, I would save up and keep winning duels or stuff to keep earning. I remember a few months back when everytime I'd win a tourney, I'd go ahead and spend what I won. This didn't turn out so well because I found myself getting poorer and poorer. Toribash kinda taught me a lesson on money managing.
Good luck, bro!