Well let me point out a few things that happen during the 2016 US election.
Trump Campaign spent around $450,000,000.
Hillary Campaign spent around $1,245,000,000.
Some left-wing individuals like to say the Trump campaign "bought" the election, but that honestly is not the case. If it was then logically with that type of thinking Hillary would have won, right? She spend nearly x3 more than the Trump Campaign. She also had the help of MSM bias, Bernie Sanders, Bill Clinton, Obama, Michelle Obama and even Joe Biden campaigning for her across the entire US to try to win her states, but nothing they did helped her win.
But if you point out things such as videos people recording at voting polls. Where voting organizers bragged about "burning" Trump voting ballots from mailed-in votes, etc. Then that is another story in itself, but as to say if elections are free depends on the situation, but there are ways to tell if it is bought or not.