Walmart offers the Thetford Porta Potti Curve Portable Toilet in White for $117.04. Choose in-store pickup to drop it to $83.24. (Amazon charges the same.) That's $2 under our March mention and the lowest price we've seen. (It's the best deal today by $42.) It features a battery-powered flush.

Update: The price at Walmart has dropped to $79.95 with in-store pickup. Amazon charges $81.58.