All Things with Love Emporium via eBay offers this Oral-B Compatible Toothbrush Head 12-Pack
with free shipping
. That's a buck under our mention from last winter and the lowest total price we've seen. (It's a current low by $2, outside of the mention below.) They feature indicator bristles and are compatible with Oral-B Vitality, Advance Power, Pro-Health Battery, ProfessionalCare, and Triumph electric toothbrushes.
A close price: Tanga
offers them for $8.88 with free shipping.