At the mothership there is an “Old Version” for $12.46 and a “New Version” for for $17.53. E-Cloth Customer Service states in a reply to a question that the only difference is the packaging. So, as is increasingly common, Woot is more expensive.
https://www.amazon.com/Cloth-Cleaning-Starter-Chemical-Free-Water/dp/B0009K6M8U?th=1