Seems like you would have some rampant inflation problems. If we build an Iron grinder, we could just build it over a zobmie/skele grinder and plant a nice big potato farm in layers surrounding the grinder so the mobs keep coming. This keeps the iron chunk loaded and you could just go back and forth between xp and potatoes. It would be nice if there was some kind of market cap. It seems to me it would make more sense to us a non-renewable resource. If inflation gets too bad it would make it impossible for someone who doesn't want to spend ages replanting potatoes to participate in the market. I would prefer currency to be a byproduct of mining if at all possible. Flint maybe considering it is pretty useless once the skele grinders get going. edit: I guess you could always buy in to the market, but at that point I'd rather just trade like we normally do. Something I have too much of for something I don't have enough of.