Alibaba, Made-in-China, or IndiaMART for low-volume prototypes ($0.16 - $8+ range depending on material/complexity), focusing on brass or aluminum; for quality, domestic options (like for 3D printing) use specialized suppliers (e.g., Printed Solid) but expect higher costs ($10-$50+ for custom/specialized nozzles). Key factors are material (brass is cheap), volume (higher MOQ means lower per-piece price), and complexity (CNC brass nozzles can be under a dollar at scale).