Any additional cost on top of the 'natural' costs involved with producing a result raises prices.
Additional costs that direct resources to a government are a form of a tax, this includes direct taxes at the point of sale, and it should also include taxes incurred for traversing an arbitrary interface (tariff or toll).
Any form of tax on goods / services proportionately effects those who spend more of their income on those goods / services more. Tariffs on not-luxury goods are regressive taxes on the poor and middle class.
Additional costs that direct resources to a government are a form of a tax, this includes direct taxes at the point of sale, and it should also include taxes incurred for traversing an arbitrary interface (tariff or toll).
Any form of tax on goods / services proportionately effects those who spend more of their income on those goods / services more. Tariffs on not-luxury goods are regressive taxes on the poor and middle class.