A long long time and many bikes ago, was my first bike, ever since then, i have been modding it, from bikes to big wheels and wagons. When i first put Cold Cathodes on my bike, and since the thought, i have considered LED's but thought it was too expensive, and they still are. But in the long run with the amount of batteries i have used through out the time on my old bike and new bike, it has been expensive.
Cold Cathodes, although cheap, as with not being energy efficient, weren't very durable. And broke from time to time. Even just the cords. One more flaw in the design was the small fuse in the 12v to 600v inverter was irreplaceable; or hard.