NPC kills

So i just had this idea hit me while i was playing today, but what if we could duel the NPCs in exchange for something special? obviously ash and gold are out of the question bc of the economy, but maybe GF points? or maybe it could give you a free relic, or a free (dis)enchantment of your choice. or put all of them in and different NPCs give out different things. now to make it to where killing the NPC is fair and equal for everyone, the sur NPCs will be killable to sur bound chars at say lvl 500? and all off sur NPCs killable at a minimum lvl 1500? this isnt much to change the economy of the game, but why does every update have to be focused on that? this is something that i think could be fun if done right. NPCs could be like a beast in that you can only kill each NPC once a month. most of them should be weaker than beasts in some places so that its not just the ubers benefiting from this, but also have a couple strong one's with better benefits so they get something out of this too. leave some constructive criticism, no "this is dum, u r teh nubcake," and if you have any ideas of what you think should drop off an NPC post it here too!