I didn't know the purple potatoes are so hard to come by. Cornell University does a huge study in potatoes. In fact our good neighbor use to head the department - we sometimes lovingly call him the Potato man! We have the normal white & yellow (finger yellows are my favorite)
variety and red potatoes and these purple kinds - its nice to mix them all up and present them in one bowl. There is a potato festival in fall - I will post about it. They even sell potato ice cream!