[imported_Eru]

I think it's bound for the same reason reward items are. It's mean to be a reward for the player that earned it through either skill-gain or hitting the 10K fame mark and paying 200K gold.

Otherwise, you could get to 10K fame, buy 10 shields, then stick them all on your vendor for 250K or so. People would pay the extra 50K to not have to worry about fame and the idea of a reward shield goes out the window.