I doubt their high speed, low flying- maneuvering target interception capability. you may get that capability via S 400.
Opposing to what you doubt, S400 is something superior to any existing air-defence system. People generally put Barak8 on the level of S300.
http://missilethreat.com/barak-gets-bigger-and-better/
The main reason India wants Barak8 is as same as Israel, she need a air-defence system to cover her own navy boat.
This weapon was late 80-90's. All Plans were awry. Its not that Soviets never had any hyper-sonic cruise missiles before. They had plenty. But its only now they are planning to integrate with Submarines. US sees Brahmos like weapon from Russia as threat in Black Sea and elsewhere.
So, US and you agree with me, supersonic cruise missile is more suitable for anti-ship purpose. No one was putting this kind of weapon against land target. Why? it is really a waste to use such an expensive weapon to attack numerous targets on the land. Your enemy can easily build up 20, 30 fake targets around the real one.
To defeat your air defenses from long range. Once done aircraft delivered cheaper munitions do the leg work.
Using $3.2m cruise missile to attack air-defence system? You can simply bankrupt your own army before they accumulated enough stock. At the mean time, Chinese cruise missile, as cheap as American Tomahawk, can attack your bases from thousands kilometres away in mass number.
Even Chinese short-range ballistic missile is cheaper than your brahmos. Both American and Chinese believe ballistic missile is more suitable for attacking enemy's headquarters, logistic centres.
What looks like is that Brahmos would prolly be the weapon of choice to clear those S-300 sites.
That is most stupid choice: without enough number, Brahmos won't be able to clear S-300 sites. It is like using Ferrari to do taxi job, can it do the job? of course, it can. But buying thousands of Ferrari as cab in one city? No one except fools will do it