The translation stage ‘Standa 960-0060’ sells for $399 and offers a full-step resolution of 1.25 micrometer (200 steps/turn, 250 micrometer per turn). With factor 8 or 16 microstepping, the resolution should be sufficient for interferometric experiments with visible light (156 or 78 nm resolution). The stepper can be easily controlled with an Arduino-based USB controller for a cost of less than $40, but a little soldering is required.