Understand basic ROI
If your sales revenue is $50, please confirm you want buy 100 clicks for $49. if you buy this maximum can get at least 1 sales I mean you revenue value will $50 with $49 spent. After that you want reduce your budget with advance tracking system or Adwords advanced features system. Its depend upon your skills based. if you have potential skill you may get $15 for 1 sales. this is the Adwords return on investment truth and fact..