Well, look at it this way (excluding tax)...
Two of those trays is $30 plus shipping. About $45-$50.
Two doughmates from amazon is $57, free shipping, and comes with a lid and a scraper.
Only $10-$15 difference and you get a lid and scraper.
Anytime you look at Amazon items that have "free shipping" you have to translate that.
"free shipping" translates to "no additional shipping charges"
The build the shipping cost into the items price.
Sometimes you have to look at something and tell yourself, "well, I'll never have to buy it again".