I can sell you a pen style ~10mw bluray for $80. Takes 2x NORMAL AAs not like those lazy builders on ebay who can't even be bothered making a real driver circuit.
And don't forget about The Laser Box V3.
Self contained USB recharging circuit w/rechargeable AA battery and USB cord all included.
You'd never even have to think about opening the case to change a battery as it's not necessary.
You could use 1 regular AA battery if you'd prefer, or constant power supplied from any 5 volt source.