Flights cost you around 8k for roundtrip. Delhi-Ludhina-Jalandhar-Pathankot-Srinagar-Sonmarg-Drass-Kargil-Lamayuru-Leh-Pangong tso-Nubra valley-Turtuk-Leh-Keylong-Jispa-Manali-kullu-chandigarh-Delhi follow this route. book it will cost you around 30k
Mumbai to delhi , 8K approx return ticket. Delhi leh delhi 33-35K package if you go with agencies. but if you go solo then 25-29K budget delhi leh delhi
If you wish to travel by your own without any organizer then you need 35-40k max per person (Including flights). But yesterday only Tripoto launched new trips/packes for leh and ladakh which are much cheaper and better.