Walmart offers the Cap Barbell Doorway Sit Up Bar, model no. HHC-CB1, for $5.07. Opt for in-store pickup to avoid the $5.99 shipping charge. That's tied with our February mention and the lowest price we could find by $8. It features steel construction and padded leg rests.

Update: The price has dropped to $4.88 before in-cart discount, $4.63 after.