I bought a green laser pointer for $8 at a thrift store last week (along with a bunch of other junk we don't need). It came with an 18650 lithium-ion cell and this nifty charger
The cell and charger alone would be cheap at half the price!
Interesting warning on the charger though. If you look at the picture closely, you'll see it reads "Intelligence can be positive and negat I've charge" and "quick chager, Safe and reliable".
I have no doubts about that! Is this label meant for the charger, a Chinese spy balloon, or maybe a fortune cookie?
I once worked in an optics lab, and borrowed a few thousand dollars of equipment to combine a red laser pointer and a green laser pointer, for those who wanted a yellow laser pointer in the worst way possible.
Tom