Originally Posted by blueangel
You can't sell the pattern, but you can sell what you make from it.
This is my understanding as well, after having looked into the matter when wanting to sell some items I'd knitted. It seems to be a pretty gray area; it was hard to find any definitive answers. Pattern makers can say what they want on the packaging, that doesn't mean they're right regarding copyright law. I would say that it is a courtesy to ask for permission, but not necessarily legally required.