While India has shown the world that it tends to spend billions i.e on MMRCA, Destroyers, PAKFA, LCA, Arjun Tanks, Aircraft Carriers, Nuke Subs. China and Pakistan on the other hand have gone undercover and they don't like to share the world real facts.
To prove this, China has secret projects like J-20, J-XX, J-15, J-10B, H-8 Stealth bomber, Aircraft Carriers, Drones, Helicopters. Pakistan on the other hand has been working on JF-17 Blk 2, Blk 3, Al-Khalid Tank 2, H2, H4, Shaheen 3, cruise missile like Babur and Ra'ad (that came from no where), and future armed Drones. Most info on both sides have not been disclosed to the world. It is still a mystery... our defence budget so called 'shown to the world' is inaccurate.
In the end, India's defence budget may seem unlimited/endless because they have disclosed everything to the world quite openly.