At $10 a piece.....and a "stay-lit" time of 40 hours.....I'll keep buying the lumenoks.
$10? You can buy the thill light for $3.49/ea. plus the nocks, which is what about $.50/ea.
I made mine so that they turn on when I shoot, and then I can pull on the nock and shut them back off. Easy to make, a couple grains lighter than the lumenoks, and work just as well, if not better!