My answer to choosing to buy traffic or not is this... Sooner or later you have to attempt to scale your business, and this is best done by buying (and testing) a variety of paid traffic sources. Look, the way I see it is if someone turns a profit, you keep it. If you take a loss, you try to find out why and then dump that particular traffic source temporarily or for good in some cases. Nothing worth gaining in this world, and in Internet Marketing is without risk. You know what they say, nothing ventured nothing gained.