It seemed like I would have to pay a significant amount of money for decent 18650s and a decent 18650 charger. I'm short on money, so I ordered a temporary (3x AAA) CREE Q5 LED Flashlight Torch for $7.59.
For more money, the same light is available with a bicycle mount, so I read those reviews, which commended the light while condemning the mount it came with. They paid at least $10 more than me, but they still gave it 4.7 stars.

I ordered a nice mount that can hold large flashlights in case I replace one of my flashlgihts later on, but I can still cancel the order if anyone speaks out against it. It's the Biologic FlashmountTM Light Mount from Bike Hugger ($11.99).

Now I will have two flashlights!