This is true, and the cost for a sniper post will always be less than that of an assault force.
Oh gosh! That is so cool! I want to live in your world, where everyone has to pull money out of their pockets to hire armies with guns to defend the contracts we've signed and when I walk out onto the street (which is owned by various different parties each with their own stipulations), I have to be concerned about various snipers and armies all taking care of business for others.
Like I said, I'd just rather pay taxes and get some generally consistent and mostly guaranteed infrastructure without little corporate and private wars being waged all around me, and know that most all streets are public and subject to a consistent set of laws, even if it is inefficient, because it's run by a government.