The Walmart exclusive LEGO 60th Anniversary Windmill (4000029) set is now available for purchase on Walmart.com. The set has 45 pieces and retails for $19.99 and is geared more towards the collectors. I guess they’ve learned their lesson from the first set as they are only allowing one per customer.
I’m not sure how much stock they have left since it went live about an hour ago. Also note that the 60th Anniversary House (4000028) is now sold out.