Why does everyone say there's an economy problem? There is NO economy in Opticraft because money is unlimited. Just because you have a market where you can buy/sell doesn't mean you have an economy. An economy means there is limited money available and it has to be balanced/managed carefully so a small group doesn't end up with all of it. With an unlimited money supply everyone can be rich, which means the people with no money just aren't putting in the effort to earn it. You can get rich selling cobble to the market, if you're dedicated enough, and never have to deal with another player. Proof that there is NO economy, and thus NO economy problem. You also can't balance an unlimited money supply.
I agree with the point that we don't have a true economy. The market is set with an unlimited amount of an item. A true market system would involve players selling to the market and players buying from the finite supply that has so far been collected by the market. Prices would rise and drop based on supply and demand (if we were running low on one item, the price would dramatically increase...and vice versa), and the whole system would be efficient. That would be a true economy.
Personally, I don't think our "economy" needs change because I like it just the way it is (for now). A lottery is kinda pointless unless its player-run, otherwise its just the server giving players more money. If we want a player-run economy, we must let the players run it (with little interaction from the server).