Go and check out oyo rooms as they are offering 74c/o off in hotels these days. And Actually, the main reason I'm recommending booking through oyo becoz MMT and goibibo bookings are not that much trustworthy, they can cancel your room if they get more money from another person. So choose wisely especially when you are traveling during the winter holidays.
Happy Travelling!!
I would suggest to visit chamba instead of shimla as on 25th weekend there will be a lot of rush. In chamba you can find cheap hotels and peaceful atmosphere.