Why the masters college fee in US vary too much from college to college ? Why Govt. doesn't provide any guideline for as such.?

It's called a free market economy.

Not all masters degrees are created equally.  A MBA from an Ivy League school is more valuable than an MBA from some random online university.  

State govts set fees for state schools. They vary depending on state budgets, tax revenues, local costs & other factors. There is no way any govt can control costs, especially at private schools, as govt control adds expenses! Look at what happens in towns with rent control: declines in housing quantities and qualities.

Stop looking to govt to solve your problems. You pay for what you get, and if you don't pay, you don't get.

Because ALL colleges are focused on making money. Not-for-profits just spend all the money, on things like exorbitant salaries, each year.