Good THERMOMETERS anyone?

Hi!

As my tea knowledge is expanding day by day, I’m finding that most teas are best drunk at certain temperatures. Unfortunately, I have hardly any control over the temperature of my tea because I use a cheap kettle. When the water boils, the switch turns itself off. As for specific temperatures below boiling, I’ve just been guessing my way through this.

Does anyone know of any good thermometers (preferably one that won’t make me broke) that can easily go into a kettle like this:
http://www.chefsales.com.au/images/products/products/11395.jpg

Thank you so much!