Brushette goes by the punchline "get fresh bristles for $1". You will need to get a one-time neck adapter which is retailed at $10 and every subsequent brushette is priced at $1.
From Philips Sonicare website heads are on average at $11.
From Oral-B website heads are on average at $9.
On Amazon you will find tons of knock-off. We know how these are made, it all comes down to quality, and at Brushette we equal the 2 market leaders quality.