REI Outlet offers the Acorn Women's Via Perforated Ballet Slippers in four colors (Violet pictured) for $19.73. Coupon code "OUT20" cuts them to $15.73. Opt for in-store pickup to dodge the $5.99 shipping charge. That's $17 under the lowest price we could find for a shipped pair. They're available in sizes 6 to 10, although not in all size/color combinations. Deal ends September 7.