The question asked was “how much are hot drinks at the resorts with no refillable mug”...
I’ve never been told of a limit when buying a paper cup for coffee. But I personally won’t keep such a cup all day. That’s why for me the mug is worth it pretty quickly bc I have coffee (with a refill) in the morning and decaf at night, and I personally would not be keeping that disposable cup all day.
And of course the hot drinks have nothing external keeping us from refilling disposable or refillable vessels. Since I've never been told of a limit for hot drinks, I just go with my personal sense of what’s ok.