Visible semiconductor sources are dirt cheap. You can buy a manual single-axis linear stage/micrometer fairly cheaply. Only one of the mirrors needs to move. They will learn a good deal about optics, beam splitters, interference, optical path-lengths and all that. They will also need to build a photodetector, so you get electronics aswell i.e. get them to do all the pre-requisite op-amp experiments. I assume most Physics Depts have access to data acquisition software so they can learn about collecting data the way modern way. As well as getting all this practical knowledge you are doing a very fundamental experiment with a very profound result. On top of all that the set-up can be extended to be used in conjunction with other applications, e.g. measure the refractive index of air, basic spectroscopic analysis, adjust it to get a fabry-perot interferometer which leads on to the Physics behind semiconductor lasers and on, and on.....