I expect an IOU costs more, and involves a bunch of priests coming to you to collect your corpse, take you to the chosen temple space, and rez you. Sort of like an NRMA membership meaning they are coming and getting you and your broken car to a mechanic.
Here's an idea for a campaign; Our heros have been hired to go collect the remains of a hero who paid for this similar-to-NRMA service.
Cleaning up after a TPK sounds like a hilarious and tense way to dungeon-crawl. Following breadcumbs left by typical murderhobos: empty vials, lesser weapons, whatever's left of some extremely deceased wildlife. Nothing left except whatever moved in when the apex predators were blasted to smithereens, and anything properly scary that the party sealed off, ran from, or somehow snuck past.
Then you finally reach several undignified stiffs - one doing the Final Fantasy face-plant, another in the Family Guy crumple, two feet sticking out under opposite sides of a giant boulder - and all of their high-level gear is strewn about, among the other treasures. You're only required to grab a meaningful portion of each body, before rapidly de-assing the area. But there's a lot of room in this wheelbarrow.
Ran a similar campaign years ago of a for-profit ambulance service in Shadowrun. Difference there was they had to extract their paying customers before they died, yet didn't know to do so until after they'd hit the panic button. Good times.