There is no price difference if I pick a flight that has a TV on each seat (with advertisement showing) or flight with an older plane that doesn't have that.

Cinema prices has not changed since they introduced several minutes of advertisement for each movie.

Buss prices in my country has not gone down when they introduced advertisement on the inside. They are currently also considering to stop having advertisement (after a political party wanted to advertise a very controversial message), but there has not been any mention of an related increase in ticket price.

Sometimes, the market price is just the price that the market is willing to pay, rather than an exact balance between costs and revenue.