That's true in the US where corruption is legal, in most other developed nations it is severely limited or forbidden, making it much less rampant and outproportioned. Here in Canada (and I assume many similarly developed countries), stories of corporate donations to political parties are often big enough scandals to make the party lose thereafter. Citizens United v. FEC has to be one of the grossest judicial change a developed country could adopt. I doubt political donation regulations are this loose even in tax havens. It didn't birth the US era of crony politics, but it sure does contribute to cement it. It's up to the people now to tackle these issues.
Wikipedia:
>The Court held that the free speech clause of the First Amendment prohibits the government from restricting independent expenditures for political communications by corporations, including nonprofit corporations, labor unions, and other associations.
Citizens United is also a threat to national security as it opens the floodgates for foreign money to directly influence American politics to an almost unlimited degree.
It may take a constitutional amendment to fix it though.
Corporations have way more money than the rest of is in politics for just this reason.
Because, as you say, at the end of the day companies will seek to lower their costs.