I can't be of any help OP, but good luck!
In the UK the circuit pack variant can be had for around £33500 (~1.47m Baht), just goes to show the crazy price hikes in Thailand!
Sounds like you've got your heart set on this car only, but I'd definitely consider an A45 AMG. I've got a 2017 C63 AMG back in London which I miss dearly, if only there was a way to bring it over to Thailand (except in a million pieces!)