Amazon.com has the 3 pack - Philips Sonicare ProResults Brush Heads for $16.
87 Using Subscribe and Save.
You can cancel your "subscription" as soon as the order ships from Amazon.
Product Link: http://www.amazon.com/dp/B000WHNI2I/?m=ATVPDKIKX0DER
You have the option to choose either "compact" or "standard".
