Never lock price. The amount you pay to lock the price will not be added and you have to pay the full price that you locked at even though they say that you have to pay remainder of the amount. I had locked price at 6700 with 1500 advance. At the time of the booking had to pay full 6700. So I had to pay total 8200 for a flight which is currently priced at 7400. Do not trust MakeMyTrip.