Unless someone gives them to you as a gift I don't think its possible to buy second hand clubs. I'm sure if you could, there would be loads of posts up with people trying to sell their old clubs. When you start to buy clubs and you advance through the levels, better clubs become available to you in the pro shop and then you can sell back your old clubs to the pro shop for quarter the price. (I thinks it quarter but dont quote me.) So basically, you wouldn't be paying full price for the clubs anyway. The only ones you can't sell back are the starter and beginner clubs.
Hope this helps.