I find it happens somewhat sooner, at the point where the PCs can afford to pay an NPC to cast Raise Dead for them.
That was unreliable on all kinds of grounds, including having the cash and a cleric of that level being anywhere they could reach. In the first case, keep in mind it wasn't uncommon when you lost someone, the group lost more than one.
Playing more than one at a time is highly recommended at low levels around here.
Its one of those things that back in day around where I played seem to go to one of two extremes: taken as a given, or considered a faux pas to even suggest.