Interactive Spirit via Amazon offers the Bombex Detangling Hair Brush 2-Pack for $12.79. Coupon code "W6UAJWCW" drops it to $8.95. Plus, Prime members bag free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $5.48.) That's a savings of $31 and the lowest total price we could find. It includes one purple and one pink brush.

Update: The price has dropped to $10.99 before coupon, $7.69 after.