Who is controlling the prices the Government or the merchants..?

Most of the time, you're the one deciding the prices for your products and services.

If you've a distributor agreement with your principal, there's usually a condition on pricing matters. This clause will ensure that the distributor does not go against the price policy set. Of course you don't want to bend the rules of the agreement, for you may be sued, and lose your reputation in the industry.

Govt too decides pricing, for example transport fares, ERP, hospitalization fees...

So long as your product is priced in a way that positions itself from competitors, then consumers will buy from you. However, if Company A sells at twice the price offered by Company B for the same product offered, then consumer might complain to CASE.

Hope i've answered this question well.

We are. Prices go DOWN when we stop buying something... And UP when we start hoarding or buying too much... WE are the Ultimate "Controllers..."