Gold Sellers - How do you defeat them?

Myself, I have no issue with Gold Sellers.
I know so many do.

But, really, what do they do but eat up the economy.

If you play the game as is, do you really need an economy? Is the economy such a needed commodity to play your MMO of choice?

I digress. What I guess we need to ask is..is there a way to eliminate the Gold Seller?
There are many facets of the MMO that could be changed to get rid of these nuisances.
Lets see how these play out...

A strange phenomenon has been noted in relation to Gold Sellers and in game Auction Houses.

Lets take some popular games that have an AH, and note something..
Do a Google search for the terms "Game name" and gold

For example:
WoW gold - 13.6 million pages (to be expected)
WAR gold - 13.1 million pages (Note the huge amount of sites already)
Or how about smaller games
LOTRO gold - 3.5 million
AoC gold - 3.5 million

Now, take a game without an AH

Guild Wars gold - 1.5 million pages

That is still a lot of pages. But, it does show a trend of AH in game and the relation of gold sellers.

Bind on Pickup - All color coded items should be BoP. Period.
I know this sucks. But, if the developer would take just a moment to make sure items that drop correlate to the class, and make them BoP, we would see less of a need for gold.
This could also kill social interaction. But, we do not know yet.

Now, another option may be make color coded items non-saleable, but tradeable.
This could bring back the social atmosphere. And make it so trade for something whether it is mats, or other items. And NOT for cash.

Create a breakables system to remove the need to buy mats.
All items in Guild Wars are breakable to some core components. Make THESE items (white class for example) break down into components for crafting if needed.
Most people pay for mats as they do not want to spend the time harvesting. Thus, some resort to gold sellers.
So, make it EASIER to get the items needed.

Force friending to trade.
You cannot announce yourself to another unless you know their name. Of course remove searchable databases for players.
This could cut into social interactions. But, this would not include "say" or "ooc". These could be open for anyone, which as we know, we can turn these off in most games.

These are a few off the top of my head.
But, do we know if this could work?
Do you have any ideas?
Voice them in comments....

Cheers.