Rekindled

Billy is actually not as well informed as you and I, he's just the average chap interested in playing the game unaware of evils such as merchanting clans. So, you can say 'well then he just payed the price for being ignorant' but you can't expect everyone to be able to look as much into a game as we do especially if you're young and unaware of the possibilities and information sites such as tipit can provide you. So in your example, the trade 'mislead' Billy into thinking 500k is the uninflated price and selling them for that amount to Billy, cheating him out of 200k. In any case it's taking advantage of someone's ignorance and cheating them out of their money which is the wrong thing to do by my standards. As Sanno said, Billy has been looking forward towards these boots for a very long time. If he's aiming to purchase them, he would at the very least look at the price to set a goal for himself before he embarked on his mission; then when he went to buy them and saw them 200k higher I would imagine he would stop and think for a second about why they've increased so much. He doesn't have to realize that the extreme rise when he's trying to buy them is caused by a merchant clan; all he needs to know is that's not the average price of the item. You don't need sites like tipit to assist you in reading the market - Jagex has very plainly made the GE graphs available to all players. Yes, it's immoral to cheat those more ignorant than you, but when they almost choose not to enlighten themselves, it's more of a matter of teaching a lesson to them by charging them a higher price than scamming.

You do not look at where the money is coming from. The extra money you're making is coming from Billy, a hard working player in the middle years of his account's existence. He's worked over hours, Billy has, just to be able to afford some decent armour. He put all his cash in the Grand Exchange and hoped for something awesome to come out, and it did! A brand new pair of shiny boots. But what's this? A week after he bought his new boots and parading about in them, one of his friends told him he just got the same boots, and he paid 200k less for them! Now this may not seem harsh for you since you're obviously too short-sighted to look beyond your big pile of cash made from all those Billys out there. But try to understand that it's not all rainbows and butterflies as you clearly think it is, not for everyone to say the least. Then he paid the price of wanting that item immediately, instead of waiting for it to become cheaper, placing his value of convenience over his principle of saving money. He chose to pay the price of wanting an item instantly rather than saving his funds and waiting longer for his item - options which the GE is designed to provide. That price change of 200k could have came from a natural crash or rise as well as an alleged manipulation; Billy would have been forced to pay an inflated price regardless if he really wanted those boots as fast as possible. If someone happened to be selling a pair of boots when the price was up at 500k, why, they've actually done Billy a favor by selling him his boots, because he's willing to pay a higher price and the seller is willing to sell the boots quickly. Billy clearly wants the boots as soon as possible, and he's lucky enough to stumble upon someone willing to provide an immediate transaction.