The great Aral Sea disaster of the Soviet Union is among the crowning achievements of what happens when prices are set by the government, not by the market. The Soviet Union sucked the Aral Sea's drainage dry to grow cotton--and then, because it had destroyed the fisheries that employed Aral Sea workers, it started flying in fish from the Arctic Ocean, thousands of miles away, to keep the cannery workers occupied. Free market prices would have prevented this. The cost of this enormous irrigation system would have showed up in the cost of what Stalin called "white gold"--the cotton produced in the Aral Sea. If you can't sell overpriced cotton, you go out of business.
Prohibiting the government from interfering with pricing would have a major positive effect: it would reduce at least a little the opportunities for corruption. But the continuing scandals of corruption require something more than a ban on govenment control of prices. It would require a complete ban on governmental interference in the economy. As nice as that sounds in theory, in practice, there are probably at least occasionally circumstances where this wouldn't be a good idea, and there's no way that such a return to Constitutional government could ever occur. I think we are going to just have to accept that bribery (whether blunt or the indirect form of "campaign contributions") is a fundamental part of our representative form of government.