Walmart offers the Stansport Portable Toilet for $14.88. (Amazon charges the same for Prime members only.) Opt for in-store pickup to dodge the $5.99 shipping charge. That's the lowest price we could find by $2. It features heavy-duty steel legs and includes six plastic bags.
3 or less star reviews on WM site. broke for most who thought this might provide actual human support. probably better used for target practice, but sit at your risk!