Hi J,
I see your point on that.
But the price is never only based on the material with what it's made. For example, the iPhone has "only" material costs of roughly $500 cost way more than double.
And this is based on multiple factors:
the ingenuity: to develop this very first non-spill cap with a push button has cost TWO YEARS of engineer manpower
it has to be patented which costs a lot of money not only for the registration but for the lawyers
its labor costs it looks like it is "just" printed on a 3d printer - while that is true it has more than only one piece and needs to be assembled, tested and again quality checked, especially with our push button. if it is not running smoothly the whole unit is trash
And since it also saves you money by not opening the bottle fully all the time with more poppers escaping than needed, and adding air to the solution which makes each push more powerful, and I do not even talk about the costs of a spilled/tipped over bottle with our first version of the topper. This is still available for $9 - you see we have reasonable prices for that, but our new version is a different beast, in the R&D and to produce it.
I hope this shine a bit more light into a "clearly just 3d printed" item with a high price.