I think everyone is right in saying that the materials themselves are more valuable than the items. My only logical answer as to why this is: Craft = EXP, and lots of it. The gear isn’t as valuable as it is to actually level up. Sure, items may be more important when endgame is reached for a majority of the cast, but the “do it yourself and get rewarded for it” is too appealing for most people.
To be honest, you would think that materials would be abundant and therefore cheap, but with things like Jute Scraps (Very difficult to find, and fetch almost twice as much as Wool) it goes against the mold. Not to mention the way people sell items on the Trading post is absurd. 1c OVER the vendor price, which then cost them 2c to list, and a fee to sell? You’re getting less of a profit.
Maybe people will figure a way to balance out the economy in the future. Who knows?