he hecho una busqueda rápida: 30€
http://www.ebay.es/itm/HD-Helmet-Sport-Action-Digital-Video-Waterproof-Camera-Camcorder-DV-1280-720-New-/161020467630?pt=AU_Video_Cameras&hash=item257d9159ae
Package Content:
1 x Mini Camcorder
1 x Waterproof Case
1 x USB data cable
1 x User manual
1 x Shield
1 x Car charger
1 x Suction Cup mount
1 x Handlebar seatpost mount
1 x Helmet mount
1 x Halmet belt
[hr]
y esta tmb podria ser interesante, por unos 27€ y con salida a tv:
http://www.ebay.es/itm/Trendy-HD-Sports-10m-Waterproof-Action-Helmet-Camera-Camcorder-USB-SD-TV-Out-/390624195980?pt=Camcorders_Professional_Video_Cameras&hash=item5af304358c