Amazon has this Regalo Swing Down Double Sided Bed Rail Guard, with Reinforced Anchor Safety System for $18.46!
SWING DOWN: The patented swing down feature allows this bedrail to pivot down and out of the way when getting in and out of bed or removing sheets
DOUBLE SIDED AND EXTRA SAFE: two rails – 43-inches long (hinge point) and 20-inch tall for added security
EASY TO SET UP: No tools required. Lightweight
SECURE: Anchoring strap that secures the bedrail to the bed. Designed with all steel frame
FIT: For use with a twin to queen size bed. ONLY for use with bed and box spring. Sturdy construction, quick installation