I don't doubt it but the gentlemen (or women) who started the post may
not be ready to invest that kind of money. I have a 'cheaper'
temperature-controlled kettle for around 75AUD but it is still about 5
degrees celcius too hot at each setting.

As long as you are aware that temperature is hard to measure and that
your instrument may not be absolutely accurate, you won't have a
problem. Your own experience is important with whatever method you use.

Adrian