In Guild Wars, you could ‘craft’ gear by taking your raw materials to the crafter NPC and exchanging them for crafted goods. In GW2, you can do effectively the same thing and sell your raw materials to the trading post (auction house), then buy the crafted goods, but this time you end up with a good profit.
This is because, as others have noted, raw materials (particularly metal, cloth, and leather) typically sell for more than the finished pieces. I imagine someone has a spreadsheet noting at what point it’s a better return to just salvage your own crafted pieces rather than selling them.
Welcome to Spinksville! 
Can’t help but sell all the jute I’ve got, despite playing mostly light armour wearers. It’s still surprising that wool is so much cheaper than jute, probably because so many people rushed up in levels with tailoring falling behind, and not having access to the TP it was harder than normal to keep up. One thing that surprisingly few people have ‘discovered’ is how to make runes, and that the ‘rare’ slivers/shards are used for this, judging by the cheap prices of those but expecting that to change when players become more informed. Discovering rare runes gives much more XP than making blue items, up to 4 skill levels.
The real curveball in the whole thing is the mystic forge, it has multiple uses and a lot of players don’t even know it exists, I can see people buying up say 4 masterwork chest armours and hoping to get a rare chest back. Even some players are buying up the cheap dyes for the chance to obtain the lucrative black/abyss/midnight/celestial colours. Crafting materials can be transmuted up a tier too, so be ready to jump on the chance when jute becomes much less expensive than wool.
Haha, I don’t really understand any of those things. Are you supposed to turn your crafted goods in at the mystic forge for a random chance of an upgrade, then?
Yep, it’s random if you put in 4 random items, but putting 4 of the same item gives back an upgrade of the same item type, usually it is a higher level requirement on the item but can be an item quality upgrade too, going from masterwork to rare, or rare to exotic.
I discovered that mystic forge in LA by mistake the other night and was all “omg what does it DO??” x) am still very confused by the crafting in GW2 and the economy. I play a light armor class myself but I think for now it’s better to wait and make some gold with my gathering.
Jute is disgustingly hard to get. All of the cloth scraps are hard to get because the only way to get it is from salvaging light armor or getting it from the “bag” items that some creatures drop. You can’t “mine for jute”. 😛
I’ve been so frustrated by the lack of economic sense of those selling for more than a copper over vendor price. (You pay for using the trading post, dangit.)
I took to vendoring all my crafted items if I need money, and tossing them into the Mystic Forge to see what comes out, if I don’t.
The TP just came up for all of us. I’m sure it will be normalized as people start to use it more. Right now I have just been selling mats, but I’m sure as people level up, gear will become worth more.
I’m not sure that I would expect this to change much as the game matures. GW2 is still an NPC-driven economy and that always seems to favor the gatherer over the crafter.
I imagine, with A.net’s strict look at the economy, if they won’t actually bump up the drop rate for those mats. Or maybe they won’t. I know they want to keep the economy very stable and healthy-preventing mass inflation and they’ve taken great pains to do so. I kinda wonder if this is going to be just fine for them, or if they’ll want to increase those drop rates. Time will tell methinks.