Well worth the price
It keeps the right temperature all day, even hot, milky tea when I was recently sick. Not needing to get up to make a new one any time I needed to soothe my throat helped. And cleaning it is simple, which is always a worry for milky drinks. Most others have fiddly bits that trap milk (or whatever you put in them), get mouldy or start to stink. My Kanteen comes apart easily, there is no fiddly scrubbing, and it goes back together without the need for several years of training in complex machinery.