i wasn't here long enough to know the past history of manipulations by players in this game, so far as i have been here about 2 years, what i have seen has been that gm/w3c has a fear/paranoid that allowing players to price their own products will provide room for them to under-price or over-price their products to gain leverages?
i don't see how this could happen if the players cannot control the ingredient costs, the number of workers, the workers' salaries, the amount of impact of the upgrades on a product, consumption rate of the products, and so on.
players have only been able to walk in a pathway that has very well gm defined side walls, floor and ceiling. as much as this game tries to stimulate "free market" economy concepts, it does not due to the control parameters that are in place, such as i mentioned. though this game does has many characteristics of a socialist, communist, or european economy as i have posted on this forum before.
in order to reduce manipulations, cheatings, etc would be to throw away the magic wand of instantly making products available for a premium price even though the world market has a huge shortage of such product, or to be selling millions of populations with the magic wand to players who can dash out the gc (via usd), or awarding trillions of dollars to warlords from money made with the magic wand.
perhaps it would be smarter if this game could learn from the america's experience since the american dollar was no longer base on the quantity of gold the country has? by this, i simply means that it seems this game is base on the american dollar, but does w3c put $0.10 US into the bank when it issues 1 gold coin to a player?