This is the cheapest head-mounted camera kit I could come up with. Welding goggles ( $3-$5 ), a strip of stretchy ribbon, ($1-$2). That's it. Cut a hole in the ribbon and mount in on your head. Rubber bands would probably do just as well.

This is definitely not meant for recording your bike ride, or anything that requires full attention from both eyes. This is meant for making videos of instructables and documenting non life-threatening activities.

instructions to make your own. instructables.com/id/Headmount-for-compact-cameras/