GW2 Spidy is a great resource, but it has one huge issue here. Please correct me if I'm wrong, though; I haven't used it much! The site calculates crafting cost based on the "Buy Now" price for raw components....which is something you would never want to do. The big issue here is that it will report things as a net loss, where there is actually a gain because you'd never do that.
So instead I've kept my own spreadsheets for items I craft...but I'd love to find a better tool! Things I'd want to see:
* Items I can profit from by crafting/buying in the most efficient way possible
* Options on if I buy some pieces (say, an insignia) and craft others myself
* Are there items out there right now I could "buy now" the materials, take the highest offer, and still make a profit? This right here would be worth mounds of gold.
Thinking about having those things makes me want to go look at the API...
@Abba, unfortunately, the recipe drop I'm referring to is account bound.
That's where the huge profit margin comes in - many people simply can't make this, and so the limited availability and knowledge of its existence = profit. I didn't know these things existed until I got one, then looked up the cost/crafting requirements and went

. The ring
Plague is made from a recipe that drops in CM exp, and sells for
23-31.5g per ring. Like Nightmare Coil, it requires only 3 dungeon runs and a bit of silver to craft. Yes, we're talking
7-10g per CM run profit for doing that dungeon. I can only assume these costs will go down over time, but that is absolutely the highest non-TP income I know of right now, other than hitting the RNG lottery.
If you need me...I'll be in TA...