Ariocarpus agavoides is a very uncommon plant and were supposed to be sold in spring but a grasshopper ate the tops off of the plants. The 2 year old plants regrew and look very healthy. These plants are around 1cm in size across, root is much larger. They have tuberous roots and are getting some growth. Normally a large plant would cost some serious money so these are small and priced I hope accordingly.
I do not guarantee these in a zone 5/6/7 because everyones growing conditions are different but this would be a good trial plant to grow in your cold outdoor garden. Try to plant outdoor 90 days before 1st hard freeze.