Where do all the 16th series come from?
Why are 16th Series Wacky Packages so Expensive?

As of the start of 2004, the overwhelming majority of the 16th series stickers that are seen going around these last few year come from one full case which was owned by a woman in the mid-West. She sold it off as full boxes back in 1998-1999. A case contains 24 boxes, each of which contains 36 packs with 3 stickers each, so a total of 2592 stickers, or about 80 complete sets. This source probably represents some 90% or more of the 16ths going around. Not all of them were opened however, several collectors maintained full boxes. The first boxes went for a couple hundred dollars each, until the seller got wise. By the end boxes were worth an easy 1K each and today with sets going for $1000 they're worth even more. What will happen if nobody finds another load of unopened stuff? Hard to predict, but the price of 16th probably will continue to rise as more people try to piece together a complete run. Time will tell...

When stores returned stuff to Topps that didn't sell, like the 16th series, Topps would not generally destroy them, they would dump them cheap to dealers who would warehouse them. There are undoubtedly warehouses full of stuff, somewhere is a ton of 16th series wackys. But will they ever see the light of day? Were they maybe destroyed in a flood or left abandoned and rotted? Who knows, but most likely Topps did not destroy them.

It's scary to imagine what sets of 16th would be going for if that case had not turned up, there would be very very few to go around.