Well if there is a connectivity of flight to your source and destination, you can opt for Flight as it is low cost or at par with Railways 1AC & some times 2AC also. some times you can get good offers on flight ticket costing as same as 3AC.
Once I traveled by Jet Airways from Lucknow to Mumbai and the ticket cost me Rs.2200/- only. I got the discounted ticket in an offer but you can easily book ticket in 30days advance to get the right price.
The ticket cost in...
more... Railways for the same route is 3915/- for 1AC, 2285/-for 2AC, 1580/-for 3AC
Traveling time in train from LKO to CST is 24 hours but in flight it just 2 hours + 1 hour extra for check in.