There is not even a single example in modern military history, of a foreign force having been able to completely crush a local armed insurgency. Not even US could do it. Not even USSR.
In Bahrain, the situation is different, since the insurgency is not armed. Iran could change the situation but for now has decided not to. Probably because Iran sees Bahrain as the last nail to be hammered into Saudi royal family's coffin. Not the first.
That is why for Pakistan, there is no strategic gain to be had in Yemen. Only monetary benefit.
That 7 or 10 billion dollar you mentioned, will not change Pakistan's destiny. Pakistan has had these kind of payments all along its history. Whether when they had sent soldiers on the order of US to fight in Korea of 1950's or when they were the Saudi-American proxy against USSR in Afghanistan or when they became an American proxy in war on terror.
Now Pakistan becoming a Saudi proxy in Yemen, will not change the destiny of Pakistan if it is paid only 7-10 billion dollars.
By comparison, Egypt which has itself a geostrategic interest in Yemen in the form of the choke-point of Bab-al-Mandeb, which has the potential to kill the only Egyptian resource asset, the Suez Canal, has been paid tens of billions of dollars by Saudis just to provide a token force and a lip service in political support for Saudis in Yemen. Similar is the case of Turkey, which is providing lip service to Saudi cause, while Saudis and other Arabs have invested hundreds of billions of dollars in Turkey and provided tens of billions of dollars easy finance to Turkish economy.
This is the moment of truth for Pakistan.
If the "brother" is rich and wants you to do the dying part on his behalf, then this brother surely would have no problem to share a very small part of its wealth with your family.
After all what is 350 billion dollars for a country that keeps 800 billion dollars cash in foreign reserves with no debt, trillions of dollars in foreign investment in Western countries, and with about 320 billion barrels of oil equivalent in gas and oil reserves, plus making billions of dollars off the pilgrims.
These are what "your brother" is doing while he is asking you to go and die in his place in Yemen without even paying for the family you leave behind:
Saudi Arabia plans a $100 billion mega-city to help end its oil dependence | KUOW News and Information : The Saudi government says it will build a brand-new city on its western coast the size of Washington, DC — at a cost of about $100 billion. It's not imaginatively named — it's known as the
King Abdullah Economic City, pronouned "cake" (KAEC) for short...
Riyadh's $22.5b Metro a ‘race against time’ |GulfNews.com : Saudi Arabia’s capital is in a race against time to complete its $22.5 billion metro system within four years, a senior official said on Wednesday...
Saudis have been the largest weapon importer globally in 2014 and in the past 4 decades have imported hundreds of billions of dollars of weapons:
Saudi Arabia becomes biggest defence equipment importer with $9.8bn set to be spent this year | The National