Already happened with my garbage collector.
What I found funny was that when fuel prices came down, a lot of them kept the fuel surcharge until people complained enough. Also, when fuel went high, motor oil did too. Went from $1-2/qt to $5-6/qt. Crude oil and fuel prices came back down but motor oil, being less refined than fuel, never came all the way back down. Funny how that works.
Works that way with a lot of stuff. Drought? Food goes up 20%. Drought over? Food prices come down 10%.