Amazon offers the Philips Sonicare E-Series Replacement Brush Head 2-Pack, model no. HX7022/64, for $15.85 with free shipping via the directions below. That's the best deal we could find by $9 and the lowest total price we've seen. They feature angled necks and "reminder bristles" that fade when in need of replacement. To get this deal:
  1. View the Philips Sonicare E-Series Replacement Brush Head 2-Pack for $21.95
  2. clip the $5 off coupon on the product page
  3. order via Subscribe & Save for a final price of $15.85 with free shipping
Be sure to cancel Subscribe & Save after your order ships to avoid being billed for subsequent shipments.