Lucid the only problem with that is well.. Let me explain it this way, lets say a Anka hasn't been sold for 1 whole year. And someone is selling it and they are asking 500k. Arent they allowed to ask for that much? Or must they have to say they are taking offers on it or auctioning it.
Plus what is the definition artificially inflated in a avatar community to begin with? Aren't we allowed to sell anything for any prices we want? And buy for whatever price we want also?
One link to artificial inflation
definition The definition here is buying out most of the same item(s) in a marketplace and selling them at a higher price. But if someone pays a price and everyone follows that isn't artificial that describes the definition of Inflation (AKA Supply and demand.) which isn't against the rules.
So basically in this situation unless someone is buying all the DI's from everyone, then selling them at extremely high prices that would be artificial inflation. But then that contradicts the purpose of "Buying for low, Selling for High." and it will lead to what I stated above of selling a item like anka one year in the future ect.
To be honest that rule might need to be rewritten if your going to be enforcing it the way you are. But if the rule isn't changed you might as well add a marketplace system where all the prices are fixed because there wouldn't be a point for selling items in forums at all unless it was for trading them. Because prices will be controlled completely on people who run price guides and or Admins who will say what price is what.