I dont see why. Culturing cells back into stem cells is very cheap. Maybe expensive to do in bulk, but you dont need to do it in bulk. You only need maybe a dozen stem cells. The hard part would be modifying the cells to produce insulin. But once you have a retrovirus to do that, that becomes almost free considering its absurdly easy to replicate viruses. After that, youd just have to culture the cells to get more, again, very easy.
I havent read the article yet, but depending on how they reintroduce those cells back into the body is almost certainly the most expensive part excluding down investment on originally creating the virus, which only has to be done once.
Edit: see my comment below