As gamedesigner myself, I always became frustrated at players that acquire items for a low price, and resell them for more. I consider these people parasistes, that contribute nothing and live off other people's hard work and efforts. Often because players that make a lot of money with this acquired the items in a manner I find morally disgusting (scamming/exploiting game mechanics to cheat other players and take their items, or buying it from new players that do not know the value for a far too low price). There are games that attempted to stop this behaviour and forcing players to work for their items instead of trading them, the best-known example is World of Warcraft's soulbound system, where only the person that picks up the item can use it, or that the item binds to the person that first equips it, so it cannot be resold later. GuildWars has the system that customizing the item grants a bonus, at the penalty of not being able to resell it later on.
However, in my opinion, both these systems are flawed. The reason is, that the 'bind on pickup' system makes items go to waste if there is noone in the party that can use it (granted, its offset by the mechanic to disenchant the item for some components, but still there's someone out there that can use it!). Also, as the original owner of the item, why can't you do with it whatever you want, including selling it for some cash? After all, you worked hard to earn that item. The 'bind on equip' and GW's Customize system is also flawed, as people can still be scammed out of their items and people still can make a profit out of trading them.
I said I would give suggestions for these problems, so here is what I propose:
* The original owner (the one that loots it) can trade the item away, or customize it to use it himself.
* Any items received in a trade are automatically customized for the new owner, and cannot be traded on to anyone else.
Advantages:
* Huge, direct reduction of overal scamming as people cannot make a large profit off it anymore.
* Prices remain low, as rich people cannot buy up available items to resell for higher prices. Newer players can afford items now, and get along in the game faster.
* Insures that the items arrive to the people that actually need it.
Disadvantages:
* Players that enjoy trading or use this as primary income source cannot do so anymore and may be less likely to buy the game. (not that I feel any sympathy for these people, sorry, I think the game is better off without them

* Scamming can still continue at a small scale, for items a scammer wants for his own character.
Ideas? Suggestions? Opinions?