“ A possible answer to what happens to spells when a mage dies. If the spell is strong enough, say and enchantment or other permenant effect, part of the mages spirit may become lodged in the magic. It may be a way for items to gain some kind of intelligence, but a mage who has knowledge of this fact would be very hesitant about enchanting anyone or thing. He might have other plans for his afterlife than counting the change in your bag of holding.
Preists, I think, would have this sort of thing covered.”
“ Head priests of a order are buried sitting up with their skeletal hand sticking out of the ground so worshippers can still kiss his hand for a blessing.”
“ Often valuables is counted in coins, jewelry and magic items. Surprise your players by offering them cheese, wine, cloth and art as rewards and payment.”