Go with bus till Manali and take bike from Manali on rent ND then continue your trip then u feel the real view of laddakh ND budget is depend on person to person according to need but it approx 8k to 10k if u r two persons
It all depends on how do you want to explore it.
here are the options:
1. Bike from Delhi/Manali to Leh
2. Rent a Bike in Leh
3. Explore in a four wheeler if not interested with Bike.
Must Visits :
1.Day1: Leh to Kargil Via Magnet Hill on day 1 as it gonna be a good start just after acclimitazation.
2. Day2 : leh to Nubra Valley Via Kardungla Pass
3. Day3 : explore Nubra
4. Day4 : Nubra to Pangong
5. Day5 : Explore Pangong
6. Day6 : Pangon to Leh via Changla Pass
7. Day7 : Explore Leh Market and Monestries.
If you still have time, explore more like Rancho school and Army museum along with flag down event in the evening.
Hope this helps..