when you have practical monopolies created when a small group of people own everything. Try to find something in your house you use day to day that isn't made by one of the Koch Brothers companies for instance. Played any of the Saints Row games? They own those (among others). You Toilet paper was probably made by them (there's a joke in there somewhere) and a lot of your food. Plus a tonne of your energy/oil.
Also for medical care you're not really free to make choices. For one thing without 6-10 years of study you don't really have enough information. For another thing if you have cancer and need chemo you're not exactly free to say no. This is a classic mistake folks make. You're comparing the decision making processes of buying a twinkie to the process of buying a heart transplant. While you might technically be 'buying' both, the processes are really nothing alike, and frankly you wouldn't want them to be.
Tax rates can be negative if the money comes somewhere else. Think of a retailer running scams. He doesn't scam his big clients because they will sue him or send thugs around to hurt him and his family. So he scams his little clients. Basically you and I pay our taxes so the big guys that own everything can own everything.
Now, I can already here you railing against taxes again so I'll say this: It's OK to pay taxes (render unto Caesar, yadda, yadda, yadda) , as long as you're getting something for it. What I hate about being an American is that I pay about the same a Europeans but without the free health care, social safety net and economic policies that raise my wages...