code: def get_epoch_namespace_prices( block_height, units ):
      
      assert units in ['BTC', TOKEN_TYPE_STACKS], 'Invalid unit {}'.format(units)
  
      epoch_config = get_epoch_config( block_height )
  
      if units == 'BTC':
          return epoch_config['namespace_prices']
      else:
          return epoch_config['namespace_prices_stacks']
docs: get the list of namespace prices by block height