old_contents: ## These "CHOICES" are used in the SiteLocation model.
  ## They describe the different account types.
  CHOICES = [
      ('free', 'Free account'),
      ('plus', 'Plus account'),
      ('premium', 'Premium account'),
      ('executive', 'Executive account')]
  
  class Tier(object):
      def __init__(self, tier_name):
          self.tier_name = tier_name
  
      def videos_limit(self):
          data = {'free': 500,
                  'plus': 1000,
                  'premium': 5000,
                  'executive': 25000}
          return data[self.tier_name]
  
      def admins_limit(self):
          data = {'free': 1,
                  'plus': 5}
          default = None
          return data.get(self.tier_name, default)
  
      def permit_custom_css(self):
          data = {'free': False}
          default = True
          return data.get(self.tier_name, default)
  
      def permit_custom_template(self):
          data = {'executive': True}
          default = False
          return data.get(self.tier_name, default)
  
      def dollar_cost(self):
          data = {'free': 0,
                  'plus': 15,
                  'premium': 35,
                  'executive': 75}
          return data[self.tier_name]
  
new_contents: ## These "CHOICES" are used in the SiteLocation model.
  ## They describe the different account types.
  CHOICES = [
      ('free', 'Free account'),
      ('plus', 'Plus account'),
      ('premium', 'Premium account'),
      ('executive', 'Executive account')]
  
  class Tier(object):
      def __init__(self, tier_name):
          self.tier_name = tier_name
  
      def videos_limit(self):
          special_cases = {'free': 500,
                  'plus': 1000,
                  'premium': 5000,
                  'executive': 25000}
          return special_cases[self.tier_name]
  
      def admins_limit(self):
          special_cases = {'free': 1,
                  'plus': 5}
          default = None
          return special_cases.get(self.tier_name, default)
  
      def permit_custom_css(self):
          special_cases = {'free': False}
          default = True
          return special_cases.get(self.tier_name, default)
  
      def permit_custom_template(self):
          special_cases = {'executive': True}
          default = False
          return special_cases.get(self.tier_name, default)
  
      def dollar_cost(self):
          special_cases = {'free': 0,
                  'plus': 15,
                  'premium': 35,
                  'executive': 75}
          return special_cases[self.tier_name]
  
subject: Rename "data" to "special_cases" to more clearly indicate what they are