Walmart offers the Stansport Cabana Privacy Shelter for $35.14. (Amazon has it for the same price for Prime members only.) Opt for in-store pickup to avoid the $4.97 shipping charge. That's the lowest in-stock price we could find by $7, except for the mention below. It features screened windows, a mesh interior pocket, and D-style door.

A close price, Jet.com has it for $35.69 with free shipping.