[benmaraschino]

Comparison shopping arguably isn’t the intended purpose of advance care directives—which, FYI, can only go into force if the person is legally incapitated, and being in pain, however extreme, is a grey area as I’m sure you could make the case that decision-making capacity still exists. There’s also the issue of having the agent available when such an event happens, and having them be in possession of the directive.

Anyway, even then, it’s infeasible to enumerate all the possible decisions in advance—not only is it impossible to know what your costs will be ahead of time, there’s a lot of variation in cost. There isn’t going to be a single hospital in your region that’ll have the cheapest prices across the board, so it’s not as simple as “send me to the cheapest hospital”.