The second is a shower head which they price at $437.22. Again, you don't buy a shower head every year, the $400+ ones will have a 10-year warranty and are going to be of significantly better quality than what comes out of a 3-D printer.
I've bought a shower head in the past. It cost $25. Looking on amazon, there are even some in the $5 range! There are a few in the expensive range that cost hundreds of dollars, but those also include quite a bit of plumbing, polished chrome/brass, knobs, and are made of metal. Even those are over priced. It seems the "researchers" just want to amazon and clicked "sort price high to low" then picked the first results.
Guns are not number one.
I take it you've never visited the FBI's website.
The statistics conservatives were excited about a few months ago was that Rifles (not handguns, shotguns, or other) were responsible for fewer deaths than "blunt objects" (which includes clubs, hammers, etc). Of course this morphed into "Hammers kill more people than guns", but according to the statistics, guns make up over two thirds of all homicides.
We cannot command nature except by obeying her. -- Sir Francis Bacon