Standby is more like between 2watts - 10 watts. The control transformer is better at 25va, the graph is at full load
What you do with a 200-300J 14-20A 5Ohm NTC depends on your goals. You could use it as it is, or wrap a simple relay as the one below around it or add under voltage protection, auto voltage select as in post 1. Both methods of wrapping a relay consume power in the same ball park
Yeah in the US a 20watt standby comes to around 27 dollars per year, I guess the issue is more with the strain on the grid. For a city that's like $211 million which is good money for the supplier