Objective: To examine the purchasing and supply patterns of new psychoactive substance (NPS) consumers in Australia. Method: Data were obtained from a self-selected sample of 296 past-year NPS consumers, with comparisons made across dimethyltryptamine (n = 104), 2C-x (n = 59), NBOMe (n = 27), and synthetic cannabinoid (n = 22) users. Results: Most consumers (58%) nominated a friend as their main NPS source, and almost half (46%) reported that they had supplied NPS to others in the past year (predominantly “social supply”). However, when comparisons were made across NPS, NBOMe users were more likely to nominate a dealer (30%) or online marketplace (22%) as their main source and to report: supplying NPS to others (63%); supplying to strangers (29%) and acquaintances (24%); and supplying NPS for cash profit (29%). Similarly, NPS consumers who nominated online markets as their main NPS source (9%; n = 26) were more likely to have supplied NPS to others (risk ratio [RR] 1.57); supplied to strangers (RR 6.05) and acquaintances (RR 12.11); sold NPS for cash profit (RR 4.36); and to have exchanged NPS for something else (RR 3.27) than those who reported alternative primary sources. Conclusion: NBOMe consumers and those who nominated online markets as their main NPS source reported greater engagement with for-profit supply; it is unclear if these individuals have “drifted” into dealing or if they were already engaged in such activities.