Hi Shashank,
1. You should book bus till bir as fare is same for both places and if you book till baijnath then you have to pay for taxi which would be 200-300 buks extra.
2. Regarding stay option if you are visiting with friends or going on solo trip you can book a bed in zostel it would cost you around 400 per person which is quite cheap.
3. You can book paragliding package in 2000 bucks and GoPro will cost 500 extra which is quite good option.
4. For places around you can visit palampur which is 45 minute bike ride from bir.