0_before.rb

  ## BEFORE

  def listing_fee
    fee = 0
    
    if self.seller.commercial?
      fee += 400  # $4.00 listing fee
    elsif self.seller.partner?
      fee += 500  # $5.00 listing fee
    else # seller is private seller
      fee += 400  # $4.00 listing fee
      fee += ((self.images.count - 3) * 50) if self.images.count > 3   # $0.50 per image fee for more than 3 images
    end
    
    fee += 500 if self.bold?  #  $5.00 bold fee
    fee += 2000 if self.featured? # $20.00 featured fee
    
    fee
  end

1_after.rb

  ## AFTER

  def image_fee
    50 # $0.50
  end

  def commercial_listing_fee
    400 # $4.00
  end
  
  def partner_listing_fee
    500 # $5.00
  end
  
  def default_listing_fee
    400 # $4.00
  end
    
  def bold_fee
    bold? ? 500 : 0 # $5.00
  end

  def featured_fee
    featured? ? 2000 : 0 # $20.00
  end
  
  def listing_fee
    return commercial_listing_fee if seller.commercial?
    return partner_listing_fee    if seller.partner?
    default_listing_fee
  end
  
  def free_images_count
    3
  end
  
  def paid_images_count
    return 0 if images.count <= free_images_count
    images.count - free_images_count
  end
  
  def images_fee
    return 0 if seller.commercial? || seller.partner?
    paid_images_count * image_fee
  end
  
  def total_fee
    listing_fee + images_fee + bold_fee + featured_fee
  end