Guild Wars 2

If i leveled cooking to 400 on my level 1, how many levels would i gain?
Do ineed to craft all to get to 80?

Sources say about 15 levels from lvl 1, and about 10 levels from that point after per each tradeskill. I’ve only done it to skip about 20 levels before, and each craft did bring me to about 10 lvls per when I started at lvl 50. A crafting booster would probably help lessen the number of materials needed as well.

I leveled LW from 0 to 400 and got me 10 levels (20 to 30) on my engineer, so about that much. There are 8 profesions in the game, so yes, you’d need to level them all (maybe one not all the way) if you want to level up from 2 (the level you usually leave the tutorial at) to 80 by crafting

Here are guides to see what you’d need: http://gw2crafts.net/ . According to it if you follow the guides you’d need about 80g worth of purchases to level them all, but if you already have other characters at level 80 you probably already have lots of materials you won’t have to buy.

Yeah, if you are level 1 you craft up to level 15 (leveling is faster in the early game to get you hooked).

After that it’s consistently about 10 levels / craft