The Demographic of wow.

The people who affect the market for goods the most are people who use their professions for a profit. While there are always casual crafters,It is estimated that well over half of the supply for crafted goods comes from people who use addons and have multiple characters with multiple professions. Their activity is the supply half of the supply/demand relationship, and the requirement for them to level their enchanters, blacksmiths, leatherworkers, and tailors to 84 in order to unlock a large portion of their trade skill means that there is going to be fewer serious crafters meaning less supply, means higher prices.
This is certainly nice for those who lucked out and had their main (who probably would have been leveled anyways) already possessing one or two of these professions. These people have much less competition than they would otherwise have had. Unfortunately, however, it means that the consumers of these crafted goods pay much higher profit margins to these crafters.