Having read up on this concept, I'd like to suggest that we create an anti money sink because the majority of our woes comes from items and not from the coin generated. We have a myriad of ways to spend coin. It may be time to find a way to spend items like coin.Money sinks are features of the game designed to combat mudflation by removing money from the game rather than adding to it. For most games, every time a monster is killed some money and/or an item (that can often be sold for money) is created out of thin air. This event happens over and over, thousands of times every day and is the major contributing factor to mudflation. Money sinks are designed to permanently remove some of this money from the game to combat this effect.
I would suggest creating trainers that would be willing to purchase items instead of coin based on the set value of an item or items and then give you training or another service based on what you spend. If you make the value of the good cost less than purchasing these services with coin, you will break the back of the beast over you knee - you will kill merchant coin economies.
I've been doing this myself icly whenever I can. I have valuable skills and spells I can train on one of my characters, but I don't really want coin. So whenever possible I have my students pay me in trading post commodities I can use later. I end up making money with ease and they end up with the skills.
I'd advocate that if an economy system based on item sinks could create a game where Billy everywarrior takes the flaming shortswords he aquired and brings them to A trainer, and based on their value in platinum gets to train a certain amount. The change he receives could be coin, the leftovers of his transactions.
This would take a lot of coding but could work better than the current economy system. The economy is saturated by too many items for sale, the more items received, the less the value of similar or the same items. Removing this clause allows for abuse so leaving it be but implementing the item sink system could work to alleviate the stress of our current economy.
Once again, I would advocate that homemade items not work in this economy nor be sellable to merchant mobiles. That's just too easy.