Oliver didn't know what kind of loot he could take from the Boulder Crab, or even whether it would be profitable, but a warning from Nebular hung in his mind. That the higher-level types of material – material borne of things greater than Hobgoblins – weren't the sort of things that could be easily prepared. They needed some of the best alchemists to work them, and not only that, they required equally rare ingredients to bond with in order to make them somewhat usable.
In short, he was told not to expect their gold to do much for him. That reduced his Boulder Crab quest into something baser. Some that hung more closely to what Oliver was usually about. It was not coin that he sought, but strength, and with the Boulder Crab, that was what he aimed to get.