What irritates me is that I have no realistic way of selling off my 200 Choc Rabbits in a realistic amount of time, since you can't stack them into a 4-trade and at 1-a-piece, I am obtaining them quicker than selling them.
In fact, many highlevels have similar issues with adventures/buffs, but actually that may be the only way to keep these items at their (already very low) value.
Mass trades would seriously imbalance the economy.
But as you may have realized, there are some members of the community who put up 10-15 trades at the same time, for gold coins - but still make profit.
How do they do it? Well, not going into details, but if they can - you can, too.
But removing the coin sink "Trade Office" is really, really a terrible idea.
One game I know had a feature similar to the "Trade Office" where you could either spend like 10-15 minutes of your playtime to get an item from the Market by running from your current location to the sales location, or spend an additional 10% just to "buy now". People actually chose the second option. Gladly. And it served a lot to keep inflation down. But it was still bad, because players easily obtained items en masse which they should never have owned in the first place: "Lowbie content" lost it's meaning, making half the game's content a wasteland.
Another game I know had an Auction House which deducted 15% of your gains from every sale - but it still killed the game because people would rather trade than play.
I don't think that "free trade" is good for the game.
In fact, probably the coin cost of additional trades should be increased in the light of gold towers.