So you would support murder of the elderly when their public cost exceeds $500,000?
Why would you think that? Most elderly people have been productive members of society, and have made a net economic contribution to society well in excess of the costs of their late life medical care. The cost shouldn’t be borne by “the public”, but given that most of the elderly have paid into the public treasury for decades, it usually isn’t being borne by the public in the final analysis. That is less true than it used to be, as a larger portion of the population becomes lifelong welfare recipients, but is still true for the great majority. Those who could have paid in but chose instead to lead deadbeat lives should be left to a combination of whatever resources they can muster on their own and private charity.