Guild Wars 2

so here is my question: other than getting some quick levels or gold is crafting interesting or useful/essential? with the term useful i mean getting stuff for way better cost.

Is it useful? I guess …
It’s the only guaranteed way to get ascended gear but those are mostly unnecessary.

Does it save you gold to craft stuff yourself instead of buying? Usually not, at least not for lv80 stuff. Haven’t looked at the lower level stuff which is sometimes a bit weird.

I would estimate about half the items you can craft are cheaper crafted than bought. No rhyme or reason to which are cheaper to craft or not, and a lot of the things that are cheaper purchased are cheaper by orders of magnitude.
IMO it’s usually not worth the time to compare costs of crafted vs. bought, except for things that cost a lot or you need a lot of them (such as destroyer weapons or sharpening stones)
for a quick comparison, I go to spidy. well, google usually is quicker for searching spidy: http://bit.ly/1lWalrT
make sure you select the right result (with ‘recipe’ in the url); it’s usually the first result. That will tell you how much it costs to make that item, and how much that item sells for. unfortunately, you’ll have to scroll down and click on that item, or look on the TP to see how much it costs to buy it. (note: spidy uses sell listing price for everything, so your actual costs will be less if you go the buy order route)

Also when looking at crafting from a cost vs just buying point of view, remember that there are often items with the same stats that only drop as loot, which might be cheaper. The some of the named armor sets are an example. Light Dire stats are one example that I believe this is true with vs Jatoro’s armor.