3d printing is a way to extend a product's life. But I think it will prove useful for a repair guy/technician rather than for a hobbyist. Making small series of spares for a unsupported product is profitable vs used spares market. One example are vintage synthesizers. There is such demand for some spares that synths are being dismantled rather than repaired. Sometimes the upper C key (which is unique on a keyboard) can be sold for 50 bucks or more.