How to prevent collusion?

Sounds like your boss thinks his suppliers are colluding to make the parts he buys more expensive. If they are colluding and are doing it by simply calling one another on the phone and working out a price then it would be very difficult maybe impossible to prove. He may just have to make the best deal he can with them. Possibly he could pick one of them and simply move all or most of his business to this one supplier if they give him a special price - they'll then find it more profitable to stop colluding with their competitors since his competitors supply him almost nothing anyhow, but this is a tricky thing to do - not sure if it would even be workable depending on the companies and situation.

Don't do it.

be a whistleblowr.

Prevent Trump from visiting Russia

Well, the major part of this that causes the most problem is the military/industrial complex. The people who own weapons shares. They have the largest interest in screwing the taxpayer over to go and kill people, or sell weapons to anyone, like the Saudis, who are also a ten percent or higher shareholder in the weapons, drugs, (heroin), and oil and lots of other things. This gives these people an incentive to cause conflict, start wars, and in fact the Federal Reserve has the same incentive, as they lend the money, it's a private bunch of banks, and they have more power and money when the US goes to war. The private interests being against the government interest, which is therefore the public interest, and these people having a major role in government as politicians, including quite often the president of the USA, like the Bushes, is disgusting. It's criminal, it's fraudulent, corrupt, it's murderous, it has to stop. The whole system needs changing, and the start of that is with the people, telling the people about it, and getting them to wake up and smell the roses. Was 9/11 an inside job? Any way you look at it, it was caused by the rich elite, even if it was caused by their horrible oppression of the poor in Afghanistan.

never give the left so much money they get stupid with it...

Full transparency of campaign finances.

You mean the way Hillary colluded with foreign spies and the CIA to manufacture a politically damaging dossier just before the election? That collusion? Maybe you mean the way Obama and Hillary illegally colluded with the IRS to release 3 misleading pages of Trump's tax returns just before the election?

Stop voting for democrats. That would send them the loudest of all possible messages. The remaining parties would see what the voters are willing to do to punish a party so in bed with organized crime and corporatism, that they would immediately take heed.