I have searched everywhere and that's the cheapest I have found plus free home delivery
PediSure Portable Pedicure Refills.
A set of genuine PediSure extra coarse replacement rollers. Gently and safely removes hard, rough, dry, calloused and cracked skin from your feet and heels. Faster, safer and more effective than traditional metal blades and scrapers.
Provides professional salon-like results in a matter of seconds, making it perfect for home use.