One note is that using 3e's demographic information for this produces some weird results--of all editions 3e is very far on the "high-power NPCs are common" spectrum. 5e hasn't published demographic information like that (and probably won't), but 9th level-equivalent casters aren't exactly growing on trees--you might have a dozen or so per nation, lumping clerics, wizards, and druids together. And then you run into the issues of cash (3500 gp is ~ 1 year of aristocratic lifestyle), willingness, time, etc.

People who can cast resurrection are even scarcer.