BuyDig via eBay Stamina X Adjustable Height Plyo Box, model no. 20-0012, for $159.99 with free shipping. That's the lowest total price we could find by $31. It feature a steel frame, adjustable height increments, and a non-slip top surface.
Leading Living via eBay offers the Folding Anti Gravity Inversion Table for $80.47 with free shipping. That's the lowest total price we could find by $30. It features extra-long handrails, a high-tensile limiting strap, and an 8-position adjustable support.