Basically, it is '/sell' for a much, much higher price which leads to inflation and more money added into the economy, which is a bad thing because it ruins the experience for all of our players. -1
^ Honestly that makes no sense, questing would be harder then breaking melons over and over that's not even close to "hardcore" only if the quests don't involve collecting blocks e.i. kill 20 creepers, fall into lava for X seconds and live, kill 10 chickens. Stuff like that would be better but I don't know if I could be coded to always work and be stable. -1 I think the idea is fun and new but the way you want to incorporate lacks things to make it a positive one.
I don't think this is a good idea. If you want a job, talk to the players. If you want a place to sell things at higher prices, go to the market place. We don't need NPC's to do this for us. That kills the player market.