The difference is in turnaround time. With your own, the turnaround time is shorter by half or less, depending on the part. That said, it assumes you have a 3D

The difference is in turnaround time. With your own, the turnaround time is shorter by half or less, depending on the part. That said, it assumes you have a 3D printer that prints reliably without fail. The current generation of desktop 3D printers finally are pretty hands free operations for short runs.