MudBox is a 3D 'art' program I guess, and yes people use it. You can have a student license if you apply for one at the Autodesk site, which lasts a few years (pretty much means you save the money for a few years). The student license works the same way with most autodesk products to my memory, including Maya and so on.

As for using Mudbox in texturing, there is a Tori rig for it somewhere on the internet but it has issues with anything before Mudbox 2014. So yea, little heads up (I use 2015 Mudbox so it makes no difference to me).