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and how much do their expenses go up?

Not prices, expenses, for example you would have to pay for things like fire protection from for profit companies, you would have to either spend a lot of money on armaments and/or pay security private contractors, you would have to pay for pesticides to kill screw worms, and like a million other things, so how much is all that going to cost?
How will monopolies be prevented from forming?

I can't watch any more youtube videos on anarcho capitalism, I have seen a number of them. they don't adequately answer my questions. they inevitably raise more and then whoever referred me to them gets mad when I ask them.