The problem is created entirely by price limits instead of a free market system.
If there were no price controls, prices would go way up, but people would be able to purchase the items they need once they have the money for them, rather than wasting vast amounts of time trying to buy them at low prices. Low level players might have trouble initially, but they also don't need as many special items for each upgrade/expansion and they will also be able to generate funds by selling their materials for a higher price than they currently sell for. This is a pretty standard model that works well in other games.