Try to book a flight from yatra and you will see they give a discount, if you are a new user and booking from app then therewill be extra discount .but while going through app they would charge a convinience fee which would be greater than the value of the discount .more over if you would try to change your payment method then the existing price also vanishes and an additional new rate is shown .Instead try booking from the airline website which you want as there is no extra fee which you have to pay on yatra.com