OK I had heard from a farmer that the potatoes they sell at market were treated with chemicals to inhibit growth (doesn't stop it, just slows it down, meaning they sprout later than untreated potatoes) and that this chemical should be avoided in food potatoes. In fact he told me that all potato farmers grow their own plot of potatoes for their families cause of the unhealthy additives that they had to use for the commercial crops. He did indeed have a separate batch growing in his "kitchen garden".
I just tried to do a search on it and got waaaaay too much info from both sides. Each side seemed to be so entrenched in their views that I couldn't find any real info or studies proving one way or the other whether it was good or bad to use store bought potatoes. So without proof that store bought potatoes are harmful I take back my earlier comment. Plant whatever you like til someone finds some real info instead of just some emotional hoopla.
There were also a bunch of articles showing how to "chit" potatoes from the store. The seed potatoes that we buy are already aged to a certain degree so store bought need a little more time to sit before sectioning and drying. I was planning on cutting mine up tomorrow and planting them next weekend. Now I'm wondering if they should sit longer. There were articles talking about disease in potatoes that didn't "chit" properly. Or maybe I should quit reading all this stuff on the Internet. I've never had a problem growing potatoes before.