Of course that was not the total cost. That was just the cost to you at that moment. The rest is paid by the society.
The real total is probably still a lot less than the cost in the US would have been.
This is no different than the way health insurance works, though. The mechanisms for collecting money and subsidies are different and for most places, there is a much larger pool of folks paying into the system.
Also, early treatment avoids really expensive later treatment. Wait too long with an allergic reaction, and you might end up calling the ambulance, invoking ICU and so on and so on. Instead of probably a couple of pills to reduce the immune systems response.