If you ever go with me shopping you will know that every variegated plant always comes home with me, this mammillaria was no exception. 

Possibly mammillaria magnimamma priessnitzii, most of the growers don’t have their plants identified, so you’re welcome to go down the rabbit hole in Google to find out exactly what it is other than “cool”

You are purchasing this exact plant featured in a 4 inch pot it will be shipped semi-bare root.