There are lot of tour organizers who arrange group trips to Leh with inexpensive budget. You can check that. contact one of them on Mob:- 9622193291 . I thinks its 14K ppfor 6D plan. Hope it helps.
Hey, I recently did my solo trip to Ladakh and it was the most memorable trip of my life. All thanks to careful planning and right people that i met. One of the main reason i could accomplish this well within my budget is because i was able to manage cheap bike rentals at http://bikerentalia.com/. I suggest you to communicate with people as much as possible because that will help you grow your circle of nature. There is nothing like first hand information.