If you are an engineer, then chances are you probably have been making easy money off of the newly non-BOP engineering crafted pets, Lil Smoky & Pet Bombling. While the markets for Core of Earth, Essense of Fire, and Heart of Fire have been fluctuating, the market for Fused Wiring has exploded. If you have a JC and an engineer , then you can church out some easy profits as fused wirings are selling for 25-30g each, and you get a stack of 5 with each crafting. These take 2 Essence of Fire and 3 Delicate Copper Wire (made by Jewelcrafters) to make 5 Fused Wirings. Delicate Copper Wires require 2 Copper Bars each.
6 Copper Bars + 2 Essence of Fire = 5 Fused Wiring.
So check your markets, there are very few sellers of Fused Wirings, but they are required for both new pets, so you are supplying engineers that are crafting as well as supplying those that are just gathering the mats for their pets as well.
Also Big Iron Bomb has been selling well for me as well at a buyout of 25g each, as this is an ingredient in the crafting of the Pet Bombling. These are cheap to make as well, requiring just 1 silver bar, 3 iron bars, and 3 heavy blasting powder (3 heavy stone) to make 2 of these bombs.