The Master Pyraminx is basically a 4 by 4 pyraminx. You solve it differently, but it would be helpful to know how to solve the regular pyraminx first.
On Amazon, the master pyraminx that we have is $18.88. It is stickerless, and works well. It is a nice upgrade from the regular pyraminx and is solved differently. I enjoy solving the master pyraminx. There are cheaper ones, but they might not be as good. The cube shown, is an example of a stickerless cube.
You solve this cube with a lot of steps. You don't have to know how to solve the regular pyraminx, but it would be helpful. I learned with the bearded cuber, so I recommend to watch that video.