I would agree with the ideas already stated. This is a topic I've spent a lot of time considering.
My opinion is that future values will inevitably drop, as they will with most nostalgic items that aren't ongoing (unlike Spider-Man which continues to reinvent itself for new generations) as the audience for them dies off.
I've devoted a considerable amount of effort to documenting candy packaging, but in 50 years, when someone looks at a 1970's Marathon bar wrapper, it won't mean all that much to them. To us, now, it has a value and a power to return us to a time and a place. Because of that, someone might pay hundreds of dollars for it. But not in a generation or two.
I believe the same will be true for 1970's Wackys. There WILL still be collected, but the amount of folks collecting will be greatlynreduced, with the levels of vintage product remaining largely the same.
It's the circle of life, I suppose, and thinking about it bums me out a bit.., but I don't think it's going to go another way.
Of course, if new Wackys keep being produced, the appeal will not diminish, but I question that trading cards and stickers are a viable entertainment product for future generations. Perhaps Wackys will live on in another form.