Could the steppers be face-down where the PVC is, with a gear to the rods?
The orientation of the steppers in this design and the open space between them could let you run (slowly) all three rods with a large gear and a single stepper motor, with a switching interface using solenoids or some other creative printed gearing/engagement/transmission mechanism. But maybe the cost is a wash vs extra vitamins/bearings.
The orientation of the steppers in this design and the open space between them could let you run (slowly) all three rods with a large gear and a single stepper motor, with a switching interface using solenoids or some other creative printed gearing/engagement/transmission mechanism. But maybe the cost is a wash vs extra vitamins/bearings.