title: Product quantity based coupon rules for a single category products
body: <p>I am working on drupal 7.12. I need to add a quantity based coupon for a single category products.</p>
  
  <p>If I have that category product qty = 3 in cart and I apply the code it should apply on this category of product only.</p>
  
  <p>I want to apply "buy 1 at $10, buy 2 at $15 and buy 6 at $30".</p>
  
  <p>Please help how I can achieve this.</p>