Just got back from the grocery store (Wegman's). They had plenty of them. Top shelf and kind of above the Nilla Wafers. They were $4.99. Last night I was in Food Lion, which I hardly ever go to, and they didn't have them at all but I am not sure that they'd ever sold them.
So I picked up a box and decided to whip this up today as I've never tried it. What I like about it is, that as desserts go, this one's not very sweet or overbearing. The wafers themselves aren't very sweet and the whipping cream and vanilla is not sweet. So a good dessert for those that don't like things too sweet. I noticed that the Pioneer Woman (Ree Drummond) has her own version of this. Her recipe uses almost twice the amount of cream and adds 1 cup of confectioners sugar. Also made in a Springform pan but it's basically the same recipe.
Someone asked upthread if you could make this using cool whip. I'd say yes as long as the Cool Whip was really stiff enough. But not sure why you'd do that because the whipped cream was easy to make and the whole dessert would be much less cloyingly sweet without the Cool Whip.