actually, the economy depends on people's mindsets in the game... you're not looking at a majority of 20-30 year olds playing, teenagers are the majority here... so you'll have to view it in their perspective...
1) limiting 1 item to a single shop might inconvience people, as sometimes they might need to buy from a same shop a few times in a day... it's not going to be much use, since if you're really a restocker, one restock a day is enough... mgiht give others a chance, but not likely...
2) Increasing the number of expensive items IS a good idea, but TNT won't usually do that to items above 100k... they did it once in the war for medicine, but if they do it to expensive items, guess how many people (ie the owners of that specific items) would get angry? Is a risk of angering lots of people who hold the items worse than the risk of making people unhappy that they don't have enough for the item?
3/4 will only increase the amount of NP we have in neopia, with a steady influx of NP we have already in a day, there isn't much that it would do; in fact it might get worse since people might have more money, thus willing to spend more... it's all a matter of demand...
So the economy of Neopia isn't something you can change in a day or by imposing few restrictions... it's fixed by the players, and the players themselves decide how the economy of Neopia is like
Gallion Count: 55/100 Ukali Count: 30/100 Now That's A Long Long way off...