What is the penalty to dying inside Elder Tale? When people die inside Elder Tale they respawn in the Cathedral.
In the first episode a penalty for dying was mentioned. However, no specifics were given.  

Does the light novel or the manga shed some light on what the penalty (or penalties) might be?
This is covered later in the LNs (which are being translated and are available here):


Adventurers lose EXP while NPCs die for real.
However, there is an additional penalty that is not obvious: when an adventurer dies they lose some of their memories.


Major spoiler:


   If the cathedral is destroyed, adventurers cannot respawn and die for real.