As one of its daily deals, Groupon offers the Philips SoniCare Compatible Replacement Toothbrush Head 8-Pack
for shipping. (Orders over $14.99 bag free shipping.) That's $10 under the lowest total price we could find for this quantity elsewhere, although we saw them for a buck less in August. They're compatible with several Philips SoniCare electric toothbrushes. Deal ends October 18.