Earlier quoted context omitted.
Sometimes I click on Google ads just because I don't like a brand and feel a little bit of joy knowing I just cost them a dollar.
Way more than a dollar. If you really want to cost a company a pretty penny, click on the ad after searching for an "intent" to do something rather than the exact brand. Some of those Adwords cost many tens of dollars.
Each ad is given a quality score, and since your own website will be guaranteed to be the most authoritative source for a keyword search with your own branded keyword(s) in it, by default the quality of your own ads will be much higher than your competition.
This means in practice that the cost for a brand to be shown first on their own branded keywords is much lower than their average CPC, let alone the cost for their competitors to be there.