Dumping

They sell of a product cheaper than others, it's the fact of selling something abroad and with a low price.

Price fixing: you and me setting a price for a product, that's illegal, some say Pepsi and coca cola do it.

Transfer pricing: Toyota is a good example, a lot of companies do this, when they buy from each other.

Countertrade: when you're gonna pay with something else, not money, pay with another good, one of the problems is not a fair exchange involved.

Cartels: when various companies with similar products and they control the price, the best example is OPEC, they are the ones who control gas and petroleum.