I too drove around in a mad rush to pick up all the last remaining boxes on the shelves at discount prices.
After they went I racked my brains about where to get more. They obviously aren't being "phased out" because MANY restaurants and catering companies still rely on them.
With a bit of searching and some carefully placed emails I found a company that will wholesale, no questions asked, delivered to your door.
If you REALLY want NO2 this is a one of the easier ways to get it.