Perella's via Amazon offers Prime members the Escali 100% Pure Badger Shaving Brush for $6.95 with free shipping. (Non-members can spend $35 to bag free shipping; otherwise, it adds $5.01.) That's $13 off list and the lowest total price we could find. It purports to help exfoliate skin and create a rich lather.
Update: As a reader found, coupon code "NXET9NSF" drops it to $2.95 with free shipping for Prime members.