I have seen induction furnaces on several Youtube videos and what strikes is its very quick and low-energy cost operation. High temperatures (even platinum) can be acquired easily.
E.g I see on the channel luckygen01 a self made induction furnace melting steel.
But I also see a very complicated setup with oscilloscope, lots of electronics.
On ebay I find rather affordable 1kW units for low voltage. A DC power supply can be a DC welder which yields 100A.
Are such units useful for melting small amounts (200ml = 1.4kg) of cast iron ?