The item worth 9999g

There are numerous ways to make gold with engineering, such as creating pets, ranged weapons, scopes or even gnomish army knives.The best one of them in my opinion is the highest level gun they can make, the Kickback 5000 which is learnable from trainers at skill level 525. I'm usually the only one selling it because most engineers seem to prefer it's almost equivalent, the Overpowered Chicken