This is how I make a pot tuber.  I  begin with a sprout from a tuber, then I help it to root , and plant it in a 4 inch pot. Then it is grown for a year. Next, I wake it up from the following year, and use it to propagate,sprout, do cuttings,divide tubers, or plant.  I love pot tubers for the following reasons. It has lots of energy and makes lots of sprouts or cuttings quickly.  Additionally, I will  divide the tubers and make more plants. Thirdly you can just put it in ground, and the outcome will be a big,healthy,bushier, strong plant. That being said,"there is a lot of value in a pot tuber".