I was there at Easter (No premium membership then) for the Lazio game - a pretty big game for the championship at that point in the season. Couldn't find tickets in the places listed, but made sure I was at Gate B on the morning tickets went on general sale. There weren't many left, but I picked up four all together. If you're living in Turin and keep an eye on juve.com for when tickets go on general sale and can guarantee you can be there asap, I imagine you should be able to pick some up at the stadium.
Then again, maybe I was a bit lucky

. Others might have experienced otherwise...