Prashar only has one or two guest houses in starting phase of trek that is in kataula or you can stay at baggi village.on reaching top at the lake,the temple gives cheap stay in dorm at around 100 per person.
Hi Ayush, you can go up to the lake and there are many shops around the temple area which provide accomodation and food. The cost will vary around 1500rs to 2000rs, you can also bargain with them.