Staying at Ramnagar would be more economical than staying inside Corbett. The best place to stay in Corbett is Dhikala forest guest house. It will be a unique experience
Jim Corbett is really expensive for stay it is better to find options outside Jim Corbett or you xan stay at Dhikaya zone min is 10000 Rs per person for one room
I would suggest to check the website for Jim Corbett since you will get agents with whom you can bargain