I believe the current rule which states that selling items from automatic farms is illegal is in need of removing. If I spend hours of my time first teaching myself the basics of redstone and then more hours designing a fully functioning farm which is able to automatically harvest items and then even more hours collecting the resources and building this farm on MeepCraft I don't see why I shouldn't be able to make a profit off it. There is an incredible amount of effort which goes into the whole process of making automatic farms especially due to the sheer complexity of most of the designs, so if a player wants to make a profit off automatic farms, I don't see why they shouldn't be rewarded for putting in all that effort. By having the current ruling on automatic farms, redstone-ing (which is an integral part of minecraft) is pretty much removed from the game making it less fun for those who have put in the time to learn it. Redstone-ing adds a whole new economy path to meepcraft and seeing as it is an economy server, I don't see why it should be made illegal.
~ @Skwisher
I wholeheartedly agree with the principle of your argument, however, I think that the concerns on this also need to be weighed in. You can 100% have automatic farms and sell to other players uninhibited, as that generates no new economy. However, if you were to make, along with 10 other players, automatic farms that could net you 100K, or 300K a day simply by selling things into /warp shop, we're soon going to find ourselves in the same economic woes as last time. Before long we would risk seeing millions and millions enter the economy every day.
The only real solution I see in this is to nerf the prices in shop so much that you simply couldn't generate a massive sum of money, but a decent income of no more than 100k a day. However, this would come at the cost of the average player, who is trying to sell those same items, but have no mega farms.