It's $100 because it's 100% made in America. It could be a bag of dog crap and it would sell if it was 100% made in America.
Americans are always willing to pay over the top for mediocre things, if it's made in America. Kind of like how lots of people are loyal Mac fans and insist Macs are the best yet they do not use them for work or school.
'murica logic
Edit: Look at this. http://www.amazon.com/Chillz-Ice-Ball-Maker-Flexible/dp/B00KI7QZ5Y/ Makes four at once, doesn't require you to melt a huge chunk of ice (have fun freezing that huge chunk in the first place) and is only $10.