It should cost you around 20K. Including cab rent/fuel cost,interstate permit, and accomodation. Hotels in the Lansdowne valley are cheaper and also provide riverside camping options. This being a relatively off-season should give you a scope of bargaining if you book (in advance, ofcourse) directly or availing discounts for online booking.
Hello, I am from Uttarakhand and it can cost you Minimium 2000- 4000 depend on your commute as now in north India you don't have to travel by AC bus you can go by normal bus and change bus from Rishikesh.