Here’s a great deal over at Amazon. Right now they have Colgate Extra Clean Toothbrush 6-packs on sale for $4.74 when you subscribe ($4.99 without subscription), plus for a limited time you will save $5 instantly at checkout when you buy three. That makes the final price for three 6-packs just $9.22 ($3.07 per 6-pack; $0.51 per toothbrush.) Here is the link to snag this deal:
Colgate Extra Clean Toothbrush 6-packs – only $9.22 for THREE 6-packs ($3.07/6-pack; $0.51/toothbrush) with sale, subscription and instant savings at checkout!