If you wear Guthan's Set only and nothing else, when you die, you lose the Spear (hence why the 4.5m cost). If you were to pick up a c bow after you die and die again, you will lose the Helm (hence why its 2.2m cost) If you were to die Dharok's Set, you lose the Weapon first, then the helm. If you were to die with Verac's Set, you lose the helm first, then the Brassard (i believe, either that or the flail). Dont know about other sets.