A coffee ordered at the counter in France often costs meaningfully less than the same coffee delivered to a sidewalk table. The difference is formal, posted and legal.
The tariff has separate columns
French cafes must display their prices, and the display commonly distinguishes consumption at the counter from consumption at a table, with the terrace priced highest.
The customer chooses the price by choosing the location, and switching from a stool to a table after ordering changes what is owed.
Nothing about this is a tourist trap. It is the same structure locals use, and residents standing at the counter are paying the lowest tier on purpose.
Service costs more at a table
A counter order involves one transaction and no table turnover management. A terrace order involves a server crossing the room repeatedly and a table occupied indefinitely.
French custom allows a single drink to hold a table for a long stretch, so the establishment prices that occupancy into the drink rather than hurrying the guest.
Americans used to refills and a check dropped early should read the higher terrace price as rent for the seat, which it effectively is.
Service is already included in the price
Prices in French cafes and restaurants are quoted with service included, so the figure on the tariff is the figure due.
There is no expectation of an American-style percentage on top. Leaving small change after a drink is common but entirely optional.
Understanding that removes the main reason Americans overpay, which is applying a domestic tipping habit to a bill that already accounts for the server.
Location multiplies the effect
A terrace facing a famous monument carries a premium far above the same cafe's counter price, because the view is the product being sold.
Walking two streets back from a landmark square usually returns prices to the neighborhood level without any loss in the coffee itself.
The gap between a landmark terrace and an ordinary counter can be several times over, which makes it one of the larger controllable costs in a day.
How to use the system deliberately
Standing at the counter for a morning coffee and saving the terrace for one long afternoon stop captures both experiences without paying terrace rates all day.
Checking the posted tariff before sitting takes a few seconds and is entirely normal behavior, since the display exists precisely to be read.
Water served with coffee is free when requested as tap water, and a carafe on the table is standard rather than an upsell, which further reduces the running cost of sitting.