I'd rather not wind up with a "fight me just to make me useful" encounter, especially for a game that's trying to enable non-violent approaches as a viable option. On the other hand, the current setup really doesn't seem to provide anything other than a visual style, since they don't sell those books any more cheaply than the vendors in town do.
Just giving a discount isn't particularly interesting either. I suppose unique items could be added to their inventory, but making them plot-relevant somehow would be better.
