I have made my printers available to this service and while business is not brisk I have gotten two jobs that I have learned from having completed.
Below is a chart that illustrates the cost versus time to print pricing model that I have on 3D Hubs. The model is based on the time and plastic that it takes to print a "Marvin".
|3D Hubs Resolution||Layer Height||Speed (mm/m)||Startup Cost||Cost per cm^3||Cost||Time to Print|
There are two factors at work in the above model. Resolution of the print is governed by the layer height. The smaller the layer the higher the resolution, and of course, the longer it takes to print. The speed that the printer moves while extruding plastic does not impact resolution, however, it has an impact on print quality though this can vary from print to print. Obviously speed has an impact on the time to complete the print!
In either case, the longer a printer is tied up the more one needs to charge!