Walmart offers the Easy Gardener 22" Adirondack Landscape Border in White for $5.08. Opt for in-store pickup to dodge the $5.97 shipping fee. That's tied with our expired mention from four days ago and the lowest price we could find by $3. Each piece measures 22" x 6".
Note: Although the page mistakenly mentions 22 pieces, it's actually a single 22" wide border.