For Marlon Murray, although Finn Lewis claimed that there wouldn't be much used in the short term, 'not much' was still relative. For someone like Finn, even a little opportunity that slipped through his fingers could feed a family like Marlon's for quite a while. And, Finn had intentionally left plenty of profit for them in the deal.
So, once Finn confirmed what the Marlin Paker's Family traded in, he had some other ideas. Their trades included the raw material of Gene Optimization Fluid and living supplies—providing contracts for AI in architecture, enabling the building to be a smart construction controlled by AI.
Another offering was construction materials, such as temperature-controlled materials lasting the whole 365 days a year, and some fully automated home-cleaning robots, which were all living supplies. On earth, however, these things were barely exploited. Thus, even though the market for a planet wasn't too big, it was enough for a minor aristocratic family.