AI is definitely not worth a $100 premium on a 1.5 hour flight.
Business is also probably not worth it.
Quite honestly, I'd just choose between Jet and IndiGo based on most convenient timings...
If both have equally good timings, I'd choose Jet Airways(9W code) over Indigo over JetKonnect (S2 code). At least I think it would be an S2 code - I vaguely remember some talk about Jet Airways putting either 9W or S2 codes on JetKonnect flights or something. Easiest way to confuse the customer