$50? No, but we are talking about your life so it might not be crazy to spend a little more. For my commuter, I gave up on battery lights entirely and use a reliable dynohub light set. The B&M Eyc on the front and Topline Light rear work perfectly. The front light has both daytime running beam and night time mode which switches automatically using a photo cell detecting light conditions. The daytime beam is focused higher to get driver's attention. The rear also has a brake light option which is governed by a chip monitoring the input to judge deceleration. I use a Sanyo hub on a wheel built by Peter White which wasn't horribly expensive and only adds .5 watts drag compared to the extremely expensive SON 28. If $75 sounds crazy then I'm certifiable, alive, and hey, I no longer worry about batteries.

Marc