Coway Airmega 400 The Smarter Air Purifier $349 + free shipping

I believe this deal is cheaper than Amazon Prime Day deal.
Airmega 400 Air purifier $349 + Free Shipping
https://www.walmart.com/ip/Coway-…/100994024
Airmega 400S WiFi version $497 + Free Shipping
http://www.walmart.com/ip/Google-…/150937260
Airmega 300 Air purifier $309 + Free Shipping
http://www.walmart.com/ip/Coway-A…/143832382
Airmega 300S WiFi version $337 + Free Shipping
http://www.walmart.com/ip/Google-…/147862839