But that's exactly the point,
Let's say that we are at the airport and one element of price (let's name him the ambassador) is present, I want every element named APOPRICE (the security guards) to react.
Same if more ambassadors are present, so the guards know what to do.
They should not be called when the price isn't there.
The price tag is created in another script, but that isn't made by me, and is dependant for people being logged-in or not. I can't make changes to that.
Basic:
IF (element classname 'price' exists)
THEN (change the styling for all elements with ID 'apoprice')
ELSE (Hide all elements with id 'apoprice')