Campaign with Time Skips

[Lamech]

Not just time skips (or else really long campaigns) - there's also supernatural, ultra-tech, and disease-based aging "damage" to contend with. Having to face the villain with the "aging ray", or the Leech with Steal Youth, even a campaign lasting only 5 campaign years for normal humans could make Unaging, Longevity, or Extended Lifespan a big deal.

Forgot about that. Assuming those things are fairly rare it would be a five point resistance for unaging, and something weird but less for longevity. The resistance part should be sliced out of unaging. Plus that would allow it to be fairly priced if age attacks were more common.