First and foremost rule when using airtel dth, guess guess guess....
Never trust price or top up details mentioned on app, many times there r errors in it.
Now coming to confusion regarding price of above sports top ups, well at least to me it seems like they r giving subscribers option to chose only these top ups along with NCF applcable for these channels rather than paying full charges for NCF Slab. In my opinion this will not be applicable for initial slab but incase u r say having 150 SD channels and adding even 1 extra will land u in next slab hence airtel has come with these top ups to save money & avoid paying Rs. 23 NCF unnecessarily